code: public final UnbindDeviceFromGatewayResponse unbindDeviceFromGateway(
        RegistryName parent, String gatewayId, String deviceId) {
  
      UnbindDeviceFromGatewayRequest request =
          UnbindDeviceFromGatewayRequest.newBuilder()
              .setParent(parent == null ? null : parent.toString())
              .setGatewayId(gatewayId)
              .setDeviceId(deviceId)
              .build();
      return unbindDeviceFromGateway(request);
    }
docs: Deletes the association between the device and the gateway.
  
  <p>Sample code:
  
  <pre><code>
  try (DeviceManagerClient deviceManagerClient = DeviceManagerClient.create()) {
  RegistryName parent = RegistryName.of("[PROJECT]", "[LOCATION]", "[REGISTRY]");
  String gatewayId = "";
  String deviceId = "";
  UnbindDeviceFromGatewayResponse response = deviceManagerClient.unbindDeviceFromGateway(parent, gatewayId, deviceId);
  }
  </code></pre>
  
  @param parent The name of the registry. For example,
  `projects/example-project/locations/us-central1/registries/my-registry`.
  @param gatewayId The value of `gateway_id` can be either the device numeric ID or the
  user-defined device identifier.
  @param deviceId The device to disassociate from the specified gateway. The value of `device_id`
  can be either the device numeric ID or the user-defined device identifier.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails