docs: public Map<String, Map<String, TopologyAPI.Grouping>> getTargets(String componentId) {
      Map<String, Map<String, TopologyAPI.Grouping>> retVal =
          new HashMap<>();
      if (!outputs.containsKey(componentId)) {
        return retVal;
      }
      for (TopologyAPI.OutputStream ostream : outputs.get(componentId)) {
        Map<String, TopologyAPI.Grouping> targetMap =
            new HashMap<>();
        for (Map.Entry<String, List<TopologyAPI.InputStream>> e : inputs.entrySet()) {
          String targetComponentId = e.getKey();
          for (TopologyAPI.InputStream is : e.getValue()) {
            if (areStreamsEqual(ostream.getStream(), is.getStream())) {
              targetMap.put(targetComponentId, is.getGtype());
            }
          }
        }
        retVal.put(ostream.getStream().getId(), targetMap);
      }
      return retVal;
    }