public function addParam($name, $value): self
    {
        if (!isset($this->params[$name])) {
            $this->setParam($name, $value);
        }

        return $this;
    }
public function addParam($name, $value): self
    {
        if (!isset($this->params[$name])) {
            $this->setParam($name, $value);
        }

        return $this;
    }
public function addParam ( $ name , $ value ) : self { if ( ! isset ( $ this -> params [ $ name ] ) ) { $ this -> setParam ( $ name , $ value ) ; } return $ this ; }
add a argument
@param $name
@param $value
@return $this
@throws \InvalidArgumentException
add a argument