How to use the tinode-sdk.Drafty.getContentType function in tinode-sdk

render() {
    const sideClass = this.props.sequence + ' ' + (this.props.response ? 'left' : 'right');
    const bubbleClass = (this.props.sequence == 'single' || this.props.sequence == 'last') ?
      'bubble tip' : 'bubble';
    const avatar = this.props.userAvatar || true;
    const fullDisplay = (this.props.userFrom && this.props.response &&
      (this.props.sequence == 'single' || this.props.sequence == 'last'));

    let content = this.props.content;
    const attachments = [];
    if (this.props.mimeType == Drafty.getContentType()) {
      Drafty.attachments(content, function(att, i) {
        if (att.mime == 'application/json') {
          // Don't show json objects as attachments.
          // They are not meant for users.
          return;
        }
        attachments.push();
      }, this);