#import #import // https://html.spec.whatwg.org/multipage/web-messaging.html#messageport [Exposed=(Window,Worker,AudioWorklet), Transferable] interface MessagePort : EventTarget { undefined postMessage(any message); undefined start(); undefined close(); // event handlers attribute EventHandler onmessage; attribute EventHandler onmessageerror; }; dictionary StructuredSerializeOptions { sequence transfer = []; };