public function unhandle()
    {
        $is_unhandled = false;
        if ($this->is_handling && !$this->last_error) {
            if ($this->prev_exception_handler) {
                set_exception_handler($this->prev_exception_handler);
                $this->prev_exception_handler = null;
            }
            if ($this->prev_error_handler) {
                set_error_handler($this->prev_error_handler);
                $this->prev_error_handler = null;
            }
            $this->is_handling = false;
            $is_unhandled      = true;
        }

        return $is_unhandled;
    }