@Test
  public void backupResponse_whenInvocationMissing_thenNothingBadHappens() {
    Invocation invocation = newInvocation();
    long callId = invocation.op.getCallId();
    invocationRegistry.register(invocation);
    invocationRegistry.deregister(invocation);

    invocationRegistry.notifyBackupComplete(callId);
    assertNull(invocationRegistry.get(callId));
  }
  @Test
  public void normalResponse_whenInvocationMissing_thenNothingBadHappens() {
    Invocation invocation = newInvocation();
    invocationRegistry.register(invocation);
    long callId = invocation.op.getCallId();
    invocationRegistry.deregister(invocation);

    invocationRegistry.notifyNormalResponse(callId, "foo", 0, null);

    assertNull(invocationRegistry.get(callId));
  }
  @Test
  public void errorResponse_whenInvocationMissing_thenNothingBadHappens() {
    Invocation invocation = newInvocation();
    invocationRegistry.register(invocation);
    long callId = invocation.op.getCallId();
    invocationRegistry.deregister(invocation);

    invocationRegistry.notifyErrorResponse(callId, new ExpectedRuntimeException(), null);

    assertNull(invocationRegistry.get(callId));
  }