public function getFacebook()
        {
            return isset($this->_data[self::PROFILE][self::FACEBOOK_ID]) ? $this->_data[self::PROFILE][self::FACEBOOK_ID] : null;
        }
public function getFacebook()
        {
            return isset($this->_data[self::PROFILE][self::FACEBOOK_ID]) ? $this->_data[self::PROFILE][self::FACEBOOK_ID] : null;
        }
public function getFacebook ( ) { return isset ( $ this -> _data [ self :: PROFILE ] [ self :: FACEBOOK_ID ] ) ? $ this -> _data [ self :: PROFILE ] [ self :: FACEBOOK_ID ] : null ; }
Retrieves the user's facebook id.

@return int
Retrieves the user s facebook id .