public function setBodySignedLen($len)
    {
        if (true === $len) {
            $this->showLen = true;
            $this->maxLen = PHP_INT_MAX;
        } elseif (false === $len) {
            $this->showLen = false;
            $this->maxLen = PHP_INT_MAX;
        } else {
            $this->showLen = true;
            $this->maxLen = (int) $len;
        }

        return $this;
    }