pan class="parameter-name">onListen</span>(<span class="parameter" id="param-subscription"><span class="type-annotation"><a href="../dart-async/StreamSubscription-class.html">StreamSubscription</a><span class="signature">&lt;<wbr><span class="type-parameter"><a href="../dart-typed_data/Uint8List-class.html">Uint8List</a></span>&gt;</span></span> <span class="parameter-name">subscription</span></span><wbr>), </span><wbr><span class="parameter" id="asBroadcastStream-param-onCancel"><span class="type-annotatio