1. DomName('DedicatedWorkerGlobalScope.postMessage')
  2. DocsEditable()
  3. Experimental()
void postMessage(Object message, [List<MessagePort> transfer])

Source 

@DomName('DedicatedWorkerGlobalScope.postMessage')
@DocsEditable()
@Experimental() // untriaged
void postMessage(Object message, [List<MessagePort> transfer]) => _blink.BlinkDedicatedWorkerGlobalScope.instance.postMessage_Callback_2_(unwrap_jso(this), message, transfer);