public function parent($parent = null)
    {
        if ($parent === null) {
            return $this->_parent;
        }
        $this->_parent = $parent;

        return $this;
    }
public function parent($parent = null)
    {
        if ($parent === null) {
            return $this->_parent;
        }
        $this->_parent = $parent;

        return $this;
    }
public function parent ( $ parent = null ) { if ( $ parent === null ) { return $ this -> _parent ; } $ this -> _parent = $ parent ; return $ this ; }
Get or set the parent menu alias.

@param bool|null|string $parent
@return MenuItem|bool|string
Get or set the parent menu alias .