Pimcore\Tool::classInterfaceExists PHP Method

    protected static function classInterfaceExists($class, $type)
    {
        $functionName = $type . "_exists";
        // if the class is already loaded we can skip right here
        if ($functionName($class, false)) {
            return true;
        }
        $class = "\\" . ltrim($class, "\\");
        // let's test if we have seens this class already before
        if (isset(self::$notFoundClassNames[$class])) {
            return false;
        }
        // we need to set a custom error handler here for the time being
        // unfortunately suppressNotFoundWarnings() doesn't work all the time, it has something to do with the calls in
        // Pimcore\Tool::ClassMapAutoloader(), but don't know what actual conditions causes this problem.
        // but to be save we log the errors into the debug.log, so if anything else happens we can see it there
        // the normal warning is e.g. Warning: include_once(Path/To/Class.php): failed to open stream: No such file or directory in ...
        set_error_handler(function ($errno, $errstr, $errfile, $errline) {
            //Logger::debug(implode(" ", [$errno, $errstr, $errfile, $errline]));
        });
        \Zend_Loader_Autoloader::getInstance()->suppressNotFoundWarnings(true);
        $exists = $functionName($class);
        \Zend_Loader_Autoloader::getInstance()->suppressNotFoundWarnings(false);
        restore_error_handler();
        if (!$exists) {
            self::$notFoundClassNames[$class] = true;
            // value doesn't matter, key lookups are faster ;-)
        }
        return $exists;
    }