code: function (buffer) {
              this._checkState(true);
              this._addContentToLastElement();
              this._appendToReadBuffer(_gpfStringEscapeForXml(buffer.toString()));
              return Promise.resolve();
          }
docs: region gpf.interfaces.IXmlContentHandler 
  @gpf:sameas gpf.interfaces.IXmlContentHandler#characters
  @since 0.2.7