src/Debug/FileStreamWrapper.php
public function dir_readdir()
    {
        if (!$this->handle) {
            return false;
        }
        self::restorePrev();
        $success = \readdir($this->handle);
        self::register();
        return $success;
    }
public function dir_readdir()
    {
        if (!$this->handle) {
            return false;
        }
        self::restorePrev();
        $success = \readdir($this->handle);
        self::register();
        return $success;
    }
Read a single filename of a directory

@return string|boolean

@see http://php.net/manual/en/streamwrapper.dir-readdir.php