async onHandle({ cmd, data, node }, realm) {
    let res;
    let handle = handlers[cmd];
    let callbackId = data && getOwnProp(data, CALLBACK_ID);
    if (callbackId) {
      data = data.data;
    }
    try {
      if (!handle) throw data;
      if (handle === REIFY) {
        handle = true;
        res = bridge[REIFY];
        if (res) await res;
      }
      res = handle === true
        ? sendCmd(cmd, data)
        : node::handle(data, realm || PAGE);
      if (isPromise(res)) {
        res = await res;
      }
    } catch (e) {
      callbackId = 'Error';
      res = e;
    }
    if (callbackId) {
      bridge.post('Callback', { id: callbackId, data: res }, realm);
    }
  }
@property {VMBridgePostFunc} [post] - present only when the web bridge was initialized
@property {VMScriptInjectInto} [injectInto] - present only after GetInjected received data
@property {Promise<void>} [reify] - present in pre-rendered documents, resolved when it's shown