Insertar transacción

public class MyActivity extends Activity implements PaymentClient.PaymentCallback {

  private PaymentClient paymentClient;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_payment);

    paymentClient = new PaymentClientImpl();
  }

  @Override
  protected void onResume() {
    super.onResume();
    paymentClient.bind(this);
  }

  @Override
  protected void onDestroy() {
    try {
      paymentClient.unbind(this);
    } catch (Exception e) {
      Log.e(TAG, e.getMessage());
    }
    super.onDestroy();
  }

  public void doExecute() {

    InsertTransactionRequest insertTransactionRequest = new InsertTransactionRequest();
    //establecer los términos obligatorios del request

    try {
      paymentClient.insertTransaction(insertTransactionRequest, this);
    } catch (ClientException e) {
      Log.e(TAG, "Error", e);
    }
  }

  @Override
  public void onError(ErrorData errorData) {
    Log.e(TAG, "Error: " + errorData.getResponseMessage());
  }

  @Override
  public void onSuccess(Object o) {
    Log.i(TAG, "Success!");
  }
}