public function jsonSerialize() { // @codingStandardsIgnoreLine (CONTRIB-6469).
        $data = parent::jsonSerialize();
        $data['horizontal'] = $this->get_horizontal();
        $data['stacked'] = $this->get_stacked();
        return $data;
    }
public function jsonSerialize() { // @codingStandardsIgnoreLine (CONTRIB-6469).
        $data = parent::jsonSerialize();
        $data['horizontal'] = $this->get_horizontal();
        $data['stacked'] = $this->get_stacked();
        return $data;
    }
public function jsonSerialize ( ) { // @codingStandardsIgnoreLine (CONTRIB-6469). $ data = parent :: jsonSerialize ( ) ; $ data [ 'horizontal' ] = $ this -> get_horizontal ( ) ; $ data [ 'stacked' ] = $ this -> get_stacked ( ) ; return $ data ; }
Add the horizontal to the parent and return the serialized data.

@return array
Add the horizontal to the parent and return the serialized data .