return "cause=[Someday...]";
          }
        };
    AbstractFuture<Object> testFuture3 = new AbstractFuture<Object>() {};
    testFuture3.setFuture(testFuture2);
    assertThat(testFuture3.toString())
        .matches(
            "[^\\[]+\\[status=PENDING, setFuture=\\[[^\\[]+\\[status=PENDING,"
                + " info=\\[cause=\\[Someday...]]]]]");
    testFuture2.set("result string");