code: public void setFailureHandler (FailureHandler handler)
      {
          if (_failureHandler != null) {
              log.warning("Requested to set failure handler, but we've already got one. The " +
                          "conflicting entities will likely need to perform more sophisticated " +
                          "coordination to deal with failures.",
                          "old", _failureHandler, "new", handler);
  
          } else {
              _failureHandler = handler;
          }
      }
docs: Sets the failure handler which will recover from place object fetching failures. In the
  event that we are unable to fetch our place object after making a successful moveTo request,
  we attempt to rectify the failure by moving back to the last known working location. Because
  entites that cooperate with the location director may need to become involved in this
  failure recovery, we provide this interface whereby they can interject themseves into the
  failure recovery process and do their own failure recovery.