code: protected void changeState(final State newState) {
          if (state.compareAndSet(newState.oppositeState(), newState)) {
              changeSupport.firePropertyChange(PROPERTY_NAME, !isOpen(newState), isOpen(newState));
          }
      }
docs: Changes the internal state of this circuit breaker. If there is actually a change
  of the state value, all registered change listeners are notified.
  
  @param newState the new state to be set