  explicit CollectiveInitializeCommunicatorOpKernel(OpKernelConstruction* c)
      : AsyncOpKernel(c), device_type_(DEVICE_DEFAULT) {
    OP_REQUIRES_OK(c, c->GetAttr("communication_hint", &communication_hint_));
    OP_REQUIRES_OK(c, c->GetAttr("timeout_seconds", &timeout_seconds_));
    device_type_ = c->device_type();
  }
  explicit CollectiveInitializeCommunicatorOpKernel(OpKernelConstruction* c)
      : AsyncOpKernel(c), device_type_(DEVICE_DEFAULT) {
    OP_REQUIRES_OK(c, c->GetAttr("communication_hint", &communication_hint_));
    OP_REQUIRES_OK(c, c->GetAttr("timeout_seconds", &timeout_seconds_));
    device_type_ = c->device_type();
  }