public RecommendParam build() { if (!_got_url) throw new IllegalStateException( "Required field 'url' was not found for struct RecommendParam"); if (!_got_types) throw new IllegalStateException( "Required field 'types' was not found for struct RecommendParam"); return new RecommendParam( this._url, Option.make(this._got_title, this._title), Option.make(this._got_keywords, this._keywords), this._types); }