is_string

<?php             ?? $mainInformation['require-dev'][$dependency]

            ?? null;



        if ( ! is_string($mainDependencyConstraint)) {

            panic(

                "The main composer file does not depend on an adapter dependency.\n" .

                "Depedency {$dependency} from {$composerFile} is missing."

<?php function reset_function_mocks()

{

    foreach (array_keys($_ENV) as $name) {

        if (is_string($name) && substr($name, 0, 5) === '__FM:') {

            unset($_ENV[$name]);

        }

    }

<?php     private function guardAgainstInvalidMount($key, $filesystem): void

    {

        if ( ! is_string($key)) {

            throw UnableToMountFilesystem::becauseTheKeyIsNotValid($key);

        }

<?php         $connection = $this->connectionProvider->provideConnection();

        $contents = $connection->get($location);



        if ( ! is_string($contents)) {

            throw UnableToReadFile::fromLocation($path);

        }

<?php         $connection = $this->connectionProvider->provideConnection();

        $contents = $connection->get($location);



        if ( ! is_string($contents)) {

            throw UnableToReadFile::fromLocation($path);

        }