blob/master/Constraints/UrlValidator.php
     * @see https://github.com/symfony/Validator/blob/master/Constraints/Url.php
     */
    public static function url($value, $message = null, $propertyPath = null)
    {
        static::string($value, $message, $propertyPath);

        $protocols = ['http', 'https'];

        $pattern = '~^
            (%s)://                                                             # protocol
            (([\.\pL\pN-]+:)?([\.\pL\pN-]+)@)?                                  # basic auth
            (
                ([\pL\pN\pS\-\.])+(\.?([\pL\pN]|xn\-\-[\pL\pN-]+)+\.?)          # a domain name
                |                                                               # or
                \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}                              # an IP address
                |                                                               # or
                \[
                    (?:(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){6})(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:::(?:(?:(?:[0-9a-f]{1,4})):){5})(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:(?:(?:(?:[0-9a-f]{1,4})))?::(?:(?:(?:[0-9a-f]{1,4})):){4})(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){0,1}(?:(?:[0-9a-f]{1,4})))?::(?:(?:(?:[0-9a-f]{1,4})):){3})(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){0,2}(?:(?:[0-9a-f]{1,4})))?::(?:(?:(?:[0-9a-f]{1,4})):){2})(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){0,3}(?:(?:[0-9a-f]{1,4})))?::(?:(?:[0-9a-f]{1,4})):)(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){0,4}(?:(?:[0-9a-f]{1,4})))?::)(?:(?:(?:(?:(?:[0-9a-f]{1,4})):(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9]))\.){3}(?:(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])))))))|(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){0,5}(?:(?:[0-9a-f]{1,4})))?::)(?:(?:[0-9a-f]{1,4})))|(?:(?:(?:(?:(?:(?:[0-9a-f]{1,4})):){0,6}(?:(?:[0-9a-f]{1,4})))?::))))
                \]                                                              # an IPv6 address
            )
            (:[0-9]+)?                                                          # a port (optional)
            (?:/ (?:[\pL\pN\-._\~!$&\'()*+,;=:@]|%%[0-9A-Fa-f]{2})* )*          # a path
            (?:\? (?:[\pL\pN\-._\~!$&\'\[\]()*+,;=:@/?]|%%[0-9A-Fa-f]{2})* )?   # a query (optional)
            (?:\# (?:[\pL\pN\-._\~!$&\'()*+,;=:@/?]|%%[0-9A-Fa-f]{2})* )?       # a fragment (optional)
        $~ixu';

        $pattern = \sprintf($pattern, \implode('|', $protocols));

        if (!\preg_match($pattern, $value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" was expected to be a valid URL starting with http or https'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_URL, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that value is alphanumeric.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function alnum($value, $message = null, $propertyPath = null)
    {
        try {
            static::regex($value, '(^([a-zA-Z]{1}[a-zA-Z0-9]*)$)', $message, $propertyPath);
        } catch (\Throwable $e) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" is not alphanumeric, starting with letters and containing only letters and numbers.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_ALNUM, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the value is boolean True.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function true($value, $message = null, $propertyPath = null)
    {
        if (true !== $value) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" is not TRUE.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_TRUE, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the value is boolean False.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function false($value, $message = null, $propertyPath = null)
    {
        if (false !== $value) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" is not FALSE.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_FALSE, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the class exists.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function classExists($value, $message = null, $propertyPath = null)
    {
        if (!\class_exists($value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Class "%s" does not exist.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_CLASS, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the interface exists.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function interfaceExists($value, $message = null, $propertyPath = null)
    {
        if (!\interface_exists($value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Interface "%s" does not exist.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_INTERFACE, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the class implements the interface.
     *
     * @param mixed                $class
     * @param string               $interfaceName
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function implementsInterface($class, $interfaceName, $message = null, $propertyPath = null)
    {
        try {
            $reflection = new \ReflectionClass($class);
            if (!$reflection->implementsInterface($interfaceName)) {
                $message = \sprintf(
                    static::generateMessage($message ?: 'Class "%s" does not implement interface "%s".'),
                    static::stringify($class),
                    static::stringify($interfaceName)
                );

                throw static::createException($class, $message, static::INTERFACE_NOT_IMPLEMENTED, $propertyPath, ['interface' => $interfaceName]);
            }
        } catch (\ReflectionException $e) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Class "%s" failed reflection.'),
                static::stringify($class)
            );
            throw static::createException($class, $message, static::INTERFACE_NOT_IMPLEMENTED, $propertyPath, ['interface' => $interfaceName]);
        }

        return true;
    }

    /**
     * Assert that the given string is a valid json string.
     *
     * NOTICE:
     * Since this does a json_decode to determine its validity
     * you probably should consider, when using the variable
     * content afterwards, just to decode and check for yourself instead
     * of using this assertion.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function isJsonString($value, $message = null, $propertyPath = null)
    {
        if (null === \json_decode($value) && JSON_ERROR_NONE !== \json_last_error()) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" is not a valid JSON string.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_JSON_STRING, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the given string is a valid UUID.
     *
     * Uses code from {@link https://github.com/ramsey/uuid} that is MIT licensed.
     *
     * @param string               $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function uuid($value, $message = null, $propertyPath = null)
    {
        $value = \str_replace(['urn:', 'uuid:', '{', '}'], '', $value);

        if ('00000000-0000-0000-0000-000000000000' === $value) {
            return true;
        }

        if (!\preg_match('/^[0-9A-Fa-f]{8}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{12}$/', $value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" is not a valid UUID.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_UUID, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the given string is a valid E164 Phone Number.
     *
     * @see https://en.wikipedia.org/wiki/E.164
     *
     * @param string               $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function e164($value, $message = null, $propertyPath = null)
    {
        if (!\preg_match('/^\+?[1-9]\d{1,14}$/', $value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" is not a valid E164.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_E164, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the count of countable is equal to count.
     *
     * @param array|\Countable|\ResourceBundle|\SimpleXMLElement $countable
     * @param int                                                $count
     * @param string|null                                        $message
     * @param string|null                                        $propertyPath
     *
     * @return bool
     */
    public static function count($countable, $count, $message = null, $propertyPath = null)
    {
        if ($count !== \count($countable)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'List does not contain exactly %d elements (%d given).'),
                static::stringify($count),
                static::stringify(\count($countable))
            );

            throw static::createException($countable, $message, static::INVALID_COUNT, $propertyPath, ['count' => $count]);
        }

        return true;
    }

    /**
     * Assert that the countable have at least $count elements.
     *
     * @param array|\Countable|\ResourceBundle|\SimpleXMLElement $countable
     * @param int                                                $count
     * @param string|null                                        $message
     * @param string|null                                        $propertyPath
     *
     * @return bool
     */
    public static function minCount($countable, $count, $message = null, $propertyPath = null)
    {
        if ($count > \count($countable)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'List should have at least %d elements, but has %d elements.'),
                static::stringify($count),
                static::stringify(\count($countable))
            );

            throw static::createException($countable, $message, static::INVALID_MIN_COUNT, $propertyPath, ['count' => $count]);
        }

        return true;
    }

    /**
     * Assert that the countable have at most $count elements.
     *
     * @param array|\Countable|\ResourceBundle|\SimpleXMLElement $countable
     * @param int                                                $count
     * @param string|null                                        $message
     * @param string|null                                        $propertyPath
     *
     * @return bool
     */
    public static function maxCount($countable, $count, $message = null, $propertyPath = null)
    {
        if ($count < \count($countable)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'List should have at most %d elements, but has %d elements.'),
                static::stringify($count),
                static::stringify(\count($countable))
            );

            throw static::createException($countable, $message, static::INVALID_MAX_COUNT, $propertyPath, ['count' => $count]);
        }

        return true;
    }

    /**
     * static call handler to implement:
     *  - "null or assertion" delegation
     *  - "all" delegation.
     *
     * @param string $method
     * @param array  $args
     *
     * @return bool|mixed
     */
    public static function __callStatic($method, $args)
    {
        if (0 === \strpos($method, 'nullOr')) {
            if (!\array_key_exists(0, $args)) {
                throw new BadMethodCallException('Missing the first argument.');
            }

            if (null === $args[0]) {
                return true;
            }

            $method = \substr($method, 6);

            return \call_user_func_array([\get_called_class(), $method], $args);
        }

        if (0 === \strpos($method, 'all')) {
            if (!\array_key_exists(0, $args)) {
                throw new BadMethodCallException('Missing the first argument.');
            }

            static::isTraversable($args[0]);

            $method = \substr($method, 3);
            $values = \array_shift($args);
            $calledClass = \get_called_class();

            foreach ($values as $value) {
                \call_user_func_array([$calledClass, $method], \array_merge([$value], $args));
            }

            return true;
        }

        throw new BadMethodCallException('No assertion Assertion#'.$method.' exists.');
    }

    /**
     * Determines if the values array has every choice as key and that this choice has content.
     *
     * @param array                $values
     * @param array                $choices
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function choicesNotEmpty(array $values, array $choices, $message = null, $propertyPath = null)
    {
        static::notEmpty($values, $message, $propertyPath);

        foreach ($choices as $choice) {
            static::notEmptyKey($values, $choice, $message, $propertyPath);
        }

        return true;
    }

    /**
     * Determines that the named method is defined in the provided object.
     *
     * @param string               $value
     * @param mixed                $object
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function methodExists($value, $object, $message = null, $propertyPath = null)
    {
        static::isObject($object, $message, $propertyPath);

        if (!\method_exists($object, $value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Expected "%s" does not exist in provided object.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_METHOD, $propertyPath, ['object' => \get_class($object)]);
        }

        return true;
    }

    /**
     * Determines that the provided value is an object.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function isObject($value, $message = null, $propertyPath = null)
    {
        if (!\is_object($value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is not a valid object.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_OBJECT, $propertyPath);
        }

        return true;
    }

    /**
     * Determines if the value is less than given limit.
     *
     * @param mixed                $value
     * @param mixed                $limit
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function lessThan($value, $limit, $message = null, $propertyPath = null)
    {
        if ($value >= $limit) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is not less than "%s".'),
                static::stringify($value),
                static::stringify($limit)
            );

            throw static::createException($value, $message, static::INVALID_LESS, $propertyPath, ['limit' => $limit]);
        }

        return true;
    }

    /**
     * Determines if the value is less or equal than given limit.
     *
     * @param mixed                $value
     * @param mixed                $limit
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function lessOrEqualThan($value, $limit, $message = null, $propertyPath = null)
    {
        if ($value > $limit) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is not less or equal than "%s".'),
                static::stringify($value),
                static::stringify($limit)
            );

            throw static::createException($value, $message, static::INVALID_LESS_OR_EQUAL, $propertyPath, ['limit' => $limit]);
        }

        return true;
    }

    /**
     * Determines if the value is greater than given limit.
     *
     * @param mixed                $value
     * @param mixed                $limit
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function greaterThan($value, $limit, $message = null, $propertyPath = null)
    {
        if ($value <= $limit) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is not greater than "%s".'),
                static::stringify($value),
                static::stringify($limit)
            );

            throw static::createException($value, $message, static::INVALID_GREATER, $propertyPath, ['limit' => $limit]);
        }

        return true;
    }

    /**
     * Determines if the value is greater or equal than given limit.
     *
     * @param mixed                $value
     * @param mixed                $limit
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function greaterOrEqualThan($value, $limit, $message = null, $propertyPath = null)
    {
        if ($value < $limit) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is not greater or equal than "%s".'),
                static::stringify($value),
                static::stringify($limit)
            );

            throw static::createException($value, $message, static::INVALID_GREATER_OR_EQUAL, $propertyPath, ['limit' => $limit]);
        }

        return true;
    }

    /**
     * Assert that a value is greater or equal than a lower limit, and less than or equal to an upper limit.
     *
     * @param mixed  $value
     * @param mixed  $lowerLimit
     * @param mixed  $upperLimit
     * @param string $message
     * @param string $propertyPath
     *
     * @return bool
     */
    public static function between($value, $lowerLimit, $upperLimit, $message = null, $propertyPath = null)
    {
        if ($lowerLimit > $value || $value > $upperLimit) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is neither greater than or equal to "%s" nor less than or equal to "%s".'),
                static::stringify($value),
                static::stringify($lowerLimit),
                static::stringify($upperLimit)
            );

            throw static::createException($value, $message, static::INVALID_BETWEEN, $propertyPath, ['lower' => $lowerLimit, 'upper' => $upperLimit]);
        }

        return true;
    }

    /**
     * Assert that a value is greater than a lower limit, and less than an upper limit.
     *
     * @param mixed  $value
     * @param mixed  $lowerLimit
     * @param mixed  $upperLimit
     * @param string $message
     * @param string $propertyPath
     *
     * @return bool
     */
    public static function betweenExclusive($value, $lowerLimit, $upperLimit, $message = null, $propertyPath = null)
    {
        if ($lowerLimit >= $value || $value >= $upperLimit) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is neither greater than "%s" nor less than "%s".'),
                static::stringify($value),
                static::stringify($lowerLimit),
                static::stringify($upperLimit)
            );

            throw static::createException($value, $message, static::INVALID_BETWEEN_EXCLUSIVE, $propertyPath, ['lower' => $lowerLimit, 'upper' => $upperLimit]);
        }

        return true;
    }

    /**
     * Assert that extension is loaded.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function extensionLoaded($value, $message = null, $propertyPath = null)
    {
        if (!\extension_loaded($value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Extension "%s" is required.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_EXTENSION, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that date is valid and corresponds to the given format.
     *
     * @param string               $value
     * @param string               $format       supports all of the options date(), except for the following:
     *                                           N, w, W, t, L, o, B, a, A, g, h, I, O, P, Z, c, r
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     *
     * @see http://php.net/manual/function.date.php#refsect1-function.date-parameters
     */
    public static function date($value, $format, $message = null, $propertyPath = null)
    {
        static::string($value, $message, $propertyPath);
        static::string($format, $message, $propertyPath);

        $dateTime = \DateTime::createFromFormat('!'.$format, $value);

        if (false === $dateTime || $value !== $dateTime->format($format)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Date "%s" is invalid or does not match format "%s".'),
                static::stringify($value),
                static::stringify($format)
            );

            throw static::createException($value, $message, static::INVALID_DATE, $propertyPath, ['format' => $format]);
        }

        return true;
    }

    /**
     * Assert that the value is an object, or a class that exists.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function objectOrClass($value, $message = null, $propertyPath = null)
    {
        if (!\is_object($value)) {
            static::classExists($value, $message, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the value is an object or class, and that the property exists.
     *
     * @param mixed                $value
     * @param string               $property
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function propertyExists($value, $property, $message = null, $propertyPath = null)
    {
        static::objectOrClass($value);

        if (!\property_exists($value, $property)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Class "%s" does not have property "%s".'),
                static::stringify($value),
                static::stringify($property)
            );

            throw static::createException($value, $message, static::INVALID_PROPERTY, $propertyPath, ['property' => $property]);
        }

        return true;
    }

    /**
     * Assert that the value is an object or class, and that the properties all exist.
     *
     * @param mixed                $value
     * @param array                $properties
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function propertiesExist($value, array $properties, $message = null, $propertyPath = null)
    {
        static::objectOrClass($value);
        static::allString($properties, $message, $propertyPath);

        $invalidProperties = [];
        foreach ($properties as $property) {
            if (!\property_exists($value, $property)) {
                $invalidProperties[] = $property;
            }
        }

        if ($invalidProperties) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Class "%s" does not have these properties: %s.'),
                static::stringify($value),
                static::stringify(\implode(', ', $invalidProperties))
            );

            throw static::createException($value, $message, static::INVALID_PROPERTY, $propertyPath, ['properties' => $properties]);
        }

        return true;
    }

    /**
     * Assert comparison of two versions.
     *
     * @param string               $version1
     * @param string               $operator
     * @param string               $version2
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function version($version1, $operator, $version2, $message = null, $propertyPath = null)
    {
        static::notEmpty($operator, 'versionCompare operator is required and cannot be empty.');

        if (true !== \version_compare($version1, $version2, $operator)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Version "%s" is not "%s" version "%s".'),
                static::stringify($version1),
                static::stringify($operator),
                static::stringify($version2)
            );

            throw static::createException($version1, $message, static::INVALID_VERSION, $propertyPath, ['operator' => $operator, 'version' => $version2]);
        }

        return true;
    }

    /**
     * Assert on PHP version.
     *
     * @param string               $operator
     * @param mixed                $version
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function phpVersion($operator, $version, $message = null, $propertyPath = null)
    {
        static::defined('PHP_VERSION');

        return static::version(PHP_VERSION, $operator, $version, $message, $propertyPath);
    }

    /**
     * Assert that extension is loaded and a specific version is installed.
     *
     * @param string               $extension
     * @param string               $operator
     * @param mixed                $version
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function extensionVersion($extension, $operator, $version, $message = null, $propertyPath = null)
    {
        static::extensionLoaded($extension, $message, $propertyPath);

        return static::version(\phpversion($extension), $operator, $version, $message, $propertyPath);
    }

    /**
     * Determines that the provided value is callable.
     *
     * @param mixed                $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function isCallable($value, $message = null, $propertyPath = null)
    {
        if (!\is_callable($value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is not a callable.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_CALLABLE, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that the provided value is valid according to a callback.
     *
     * If the callback returns `false` the assertion will fail.
     *
     * @param mixed                $value
     * @param callable             $callback
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function satisfy($value, $callback, $message = null, $propertyPath = null)
    {
        static::isCallable($callback);

        if (false === \call_user_func($callback, $value)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Provided "%s" is invalid according to custom rule.'),
                static::stringify($value)
            );

            throw static::createException($value, $message, static::INVALID_SATISFY, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that value is an IPv4 or IPv6 address
     * (using input_filter/FILTER_VALIDATE_IP).
     *
     * @param string               $value
     * @param int|null             $flag
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     *
     * @see http://php.net/manual/filter.filters.flags.php
     */
    public static function ip($value, $flag = null, $message = null, $propertyPath = null)
    {
        static::string($value, $message, $propertyPath);
        if (!\filter_var($value, FILTER_VALIDATE_IP, $flag)) {
            $message = \sprintf(
                static::generateMessage($message ?: 'Value "%s" was expected to be a valid IP address.'),
                static::stringify($value)
            );
            throw static::createException($value, $message, static::INVALID_IP, $propertyPath, ['flag' => $flag]);
        }

        return true;
    }

    /**
     * Assert that value is an IPv4 address
     * (using input_filter/FILTER_VALIDATE_IP).
     *
     * @param string               $value
     * @param int|null             $flag
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     *
     * @see http://php.net/manual/filter.filters.flags.php
     */
    public static function ipv4($value, $flag = null, $message = null, $propertyPath = null)
    {
        static::ip($value, $flag | FILTER_FLAG_IPV4, static::generateMessage($message ?: 'Value "%s" was expected to be a valid IPv4 address.'), $propertyPath);

        return true;
    }

    /**
     * Assert that value is an IPv6 address
     * (using input_filter/FILTER_VALIDATE_IP).
     *
     * @param string               $value
     * @param int|null             $flag
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     *
     * @see http://php.net/manual/filter.filters.flags.php
     */
    public static function ipv6($value, $flag = null, $message = null, $propertyPath = null)
    {
        static::ip($value, $flag | FILTER_FLAG_IPV6, static::generateMessage($message ?: 'Value "%s" was expected to be a valid IPv6 address.'), $propertyPath);

        return true;
    }

    /**
     * Assert that a constant is defined.
     *
     * @param mixed                $constant
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function defined($constant, $message = null, $propertyPath = null)
    {
        if (!\defined($constant)) {
            $message = \sprintf(static::generateMessage($message ?: 'Value "%s" expected to be a defined constant.'), $constant);

            throw static::createException($constant, $message, static::INVALID_CONSTANT, $propertyPath);
        }

        return true;
    }

    /**
     * Assert that a constant is defined.
     *
     * @param string               $value
     * @param string|callable|null $message
     * @param string|null          $propertyPath
     *
     * @return bool
     */
    public static function base64($value, $message = null, $propertyPath = null)
    {
        if (false === \base64_decode($value, true)) {
            $message = \sprintf(static::generateMessage($message ?: 'Value "%s" is not a valid base64 string.'), $value);

            throw static::createException($value, $message, static::INVALID_BASE64, $propertyPath);
        }

        return true;
    }

    /**
     * Helper method that handles building the assertion failure exceptions.
     * They are returned from this method so that the stack trace still shows
     * the assertions method.
     *
     * @param mixed           $value
     * @param string|callable $message
     * @param int             $code
     * @param string|null     $propertyPath
     * @param array           $constraints
     *
     * @return mixed
     */
    protected static function createException($value, $message, $code, $propertyPath = null, array $constraints = [])
    {
        $exceptionClass = static::$exceptionClass;

        return new $exceptionClass($message, $code, $propertyPath, $value, $constraints);
    }

    /**
     * Make a string version of a value.
     *
     * @param mixed $value
     *
     * @return string
     */
    protected static function stringify($value)
    {
        $result = \gettype($value);

        if (\is_bool($value)) {
            $result = $value ? '<TRUE>' : '<FALSE>';
        } elseif (\is_scalar($value)) {
            $val = (string) $value;

            if (\strlen($val) > 100) {
                $val = \substr($val, 0, 97).'...';
            }

            $result = $val;
        } elseif (\is_array($value)) {
            $result = '<ARRAY>';
        } elseif (\is_object($value)) {
            $result = \get_class($value);
        } elseif (\is_resource($value)) {
            $result = \get_resource_type($value);
        } elseif (null === $value) {
            $result = '<NULL>';
        }

        return $result;
    }

    /**
     * Generate the message.
     *
     * @param string|callable $message
     *
     * @return string
     */
    protected static function generateMessage($message): string
    {
        if (\is_callable($message)) {
            $traces = \debug_backtrace(0);

            $parameters = [];

            try {
                $reflection = new \ReflectionClass($traces[1]['class']);
                $method = $reflection->getMethod($traces[1]['function']);
                foreach ($method->getParameters() as $index => $parameter) {
                    if ('message' !== $parameter->getName()) {
                        $parameters[$parameter->getName()] = \array_key_exists($index, $traces[1]['args'])
                            ? $traces[1]['args'][$index]
                            : $parameter->getDefaultValue();
                    }
                }

                $parameters['::assertion'] = \sprintf('%s%s%s', $traces[1]['class'], $traces[1]['type'], $traces[1]['function']);

                $message = \call_user_func_array($message, [$parameters]);
            } // @codeCoverageIgnoreStart
            catch (\Throwable $exception) {
                $message = \sprintf('Unable to generate message : %s', $exception->getMessage());
            } // @codeCoverageIgnoreEnd
        }

        return (string) $message;
    }
}