code: public void addEntityMimicRecorder(String id, EntityMimicRecorder mimicRecordingEntitySelector) {
          EntityMimicRecorder put = entityMimicRecorderMap.put(id, mimicRecordingEntitySelector);
          if (put != null) {
              throw new IllegalStateException("Multiple " + EntityMimicRecorder.class.getSimpleName() + "s (usually "
                      + EntitySelector.class.getSimpleName() + "s) have the same id (" + id + ").");
          }
      }
docs: ************************************************************************