public function autoload($class)
    {
        if (isset($this->classes[$class])) {
            require $this->classes[$class];

            return true;
        }
        // fallback for classes defined with leading backslash
        if (strpos($class, '\\') === 0) {
            $class = substr($class, 1);

            return $this->autoload($class);
        }

        return false;
    }