}

  public void testToString_cancelled() throws Exception {
    assertThat(immediateCancelledFuture().toString()).matches("[^\\[]+\\[status=CANCELLED\\]");
  }

  public void testToString_failed() {
    assertThat(immediateFailedFuture(new RuntimeException("foo")).toString())
        .matches("[^\\[]+\\[status=FAILURE, cause=\\[java.lang.RuntimeException: foo\\]\\]");
  }