code: @Trivial
      private void stateOpen() {
          openStateStartTime = System.nanoTime();
          state.set(State.OPEN);
          metricRecorder.reportCircuitOpen();
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "Transitioned to Open state");
          }
      }
docs: Transition to open state