public function footer(Closure $closure = null)
    {
        if (!$closure) {
            return $this->footer;
        }

        $this->footer = $closure;

        return $this;
    }
public function footer(Closure $closure = null)
    {
        if (!$closure) {
            return $this->footer;
        }

        $this->footer = $closure;

        return $this;
    }
public function footer ( Closure $ closure = null ) { if ( ! $ closure ) { return $ this -> footer ; } $ this -> footer = $ closure ; return $ this ; }
Set grid footer.

@param Closure|null $closure

@return $this|Closure
Set grid footer .