lementation</span></h2>
  <pre class="language-dart"><code class="language-dart">Future&lt;dynamic&gt; send(Map&lt;String, dynamic&gt; data, {int? handleId}) async {
  if (data[&#39;transaction&#39;] != null) {
    data[&#39;session_id&#39;] = sessionId;
    if (handleId != null) {
      data[&#39;handle_id&#39;] = handleId;
    }
    sink!.add(stringify(data));
    return parse(await stream.firstWhere((element) =&gt; (parse(element)[&#39;transaction&#39;] == data[&#39;transaction&#39;]), orElse: () =&gt; {