@Test
public void executeBlockingCall_explodes_immediately_if_circuit_is_OPEN() {

    // given
    Callable<String> supplierMock = mock(Callable.class);
    Whitebox.setInternalState(cbSpy, "currentState", State.OPEN);
    // when
    Throwable cbExplosion = catchThrowable(() -> cbSpy.executeBlockingCall(supplierMock));
    // then
    assertThat(cbExplosion)
        .isNotNull()
        .isInstanceOf(CircuitBreakerOpenException.class);
    verifyZeroInteractions(supplierMock);
}