@Test
public void isEventACircuitBreakerFailure_returns_whatever_breakingEventStrategy_returns() {

    // given
    BreakingEventStrategy<String> falseDecider = theString -> false;
    Whitebox.setInternalState(cbSpy, "breakingEventStrategy", falseDecider);
    // expect
    assertThat(cbSpy.isEventACircuitBreakerFailure("foo")).isFalse();
    // and given
    BreakingEventStrategy<String> trueDecider = theString -> true;
    Whitebox.setInternalState(cbSpy, "breakingEventStrategy", trueDecider);
    // expect
    assertThat(cbSpy.isEventACircuitBreakerFailure("foo")).isTrue();
}