public function call($method, $args = [], $expect = self::EXPECT_SELF)
    {
        if (!is_array($args)) {
            $expect = $args;
            $args   = [];
        }

        if (!$this->helper) {
            return $this->expected($expect);
        }

        return call_user_func_array([$this->helper, $method], $args);
    }