code: public synchronized void put(final EvaluatorManager evaluatorManager) {
      final String evaluatorId = evaluatorManager.getId();
      if (this.wasClosed(evaluatorId)) {
        throw new IllegalArgumentException(
          "Trying to re-add an Evaluator that has already been closed: " + evaluatorId);
      }
      final EvaluatorManager prev = this.evaluators.put(evaluatorId, evaluatorManager);
      LOG.log(Level.FINEST, "Adding: {0} previous: {1}", new Object[]{evaluatorId, prev});
      if (prev != null) {
        throw new IllegalArgumentException(
          "Trying to re-add an Evaluator that is already known: " + evaluatorId);
      }
    }
docs: Adds an EvaluatorManager.
  
  @param evaluatorManager
  @throws java.lang.IllegalArgumentException if the EvaluatorManager is already known.