future.set(result);
    assertEquals(result, future.get());
    assertThat(successCalls[0]).isEqualTo(1);
    assertThat(failureCalls[0]).isEqualTo(0);
  }

  public void testOnSuccessThrowsError() throws Exception {
    SomeError error = new SomeError();
    String result = "result";
    SettableFuture<String> future = SettableFuture.create();
    int[] successCalls = new int[1];