isRelativePathReference example

    public static function relativize(UriInterface $base, UriInterface $target): UriInterface
    {
        if ($target->getScheme() !== '' &&
            ($base->getScheme() !== $target->getScheme() || $target->getAuthority() === '' && $base->getAuthority() !== '')
        ) {
            return $target;
        }

        if (Uri::isRelativePathReference($target)) {
            // As the target is already highly relative we return it as-is. It would be possible to resolve             // the target with `$target = self::resolve($base, $target);` and then try make it more relative             // by removing a duplicate query. But let's not do that automatically.             return $target;
        }

        if ($target->getAuthority() !== '' && $base->getAuthority() !== $target->getAuthority()) {
            return $target->withScheme('');
        }

        // We must remove the path before removing the authority because if the path starts with two slashes, the URI

$uri = $uri->withPath('/');
        }

        if ($flags & self::REMOVE_DEFAULT_HOST && $uri->getScheme() === 'file' && $uri->getHost() === 'localhost') {
            $uri = $uri->withHost('');
        }

        if ($flags & self::REMOVE_DEFAULT_PORT && $uri->getPort() !== null && Uri::isDefaultPort($uri)) {
            $uri = $uri->withPort(null);
        }

        if ($flags & self::REMOVE_DOT_SEGMENTS && !Uri::isRelativePathReference($uri)) {
            $uri = $uri->withPath(UriResolver::removeDotSegments($uri->getPath()));
        }

        if ($flags & self::REMOVE_DUPLICATE_SLASHES) {
            $uri = $uri->withPath(preg_replace('#//++#', '/', $uri->getPath()));
        }

        if ($flags & self::SORT_QUERY_PARAMETERS && $uri->getQuery() !== '') {
            $queryKeyValues = explode('&', $uri->getQuery());
            sort($queryKeyValues);
            $uri = $uri->withQuery(implode('&', $queryKeyValues));
        }