code: public final InstanceState getInstanceState() {
          return isTerminated() ? InstanceState.TERMINATED
                  : (isBooting() ? InstanceState.PENDING
                          : (isStopping() ? InstanceState.STOPPING
                                  : (isRunning() ? InstanceState.RUNNING
                                          : InstanceState.STOPPED)));
      }
docs: Get state of this mock ec2 instance.
  
  @return state of this mock ec2 instance, should be one of the instance states defined in {@link InstanceState}