code: public Map<String, Map<String, Grouping>> getTargets(String componentId) {
          Map<String, Map<String, Grouping>> ret = new HashMap<>();
          for (String otherComponentId : getComponentIds()) {
              Map<GlobalStreamId, Grouping> inputs = getComponentCommon(otherComponentId).get_inputs();
              for (GlobalStreamId id : inputs.keySet()) {
                  if (id.get_componentId().equals(componentId)) {
                      Map<String, Grouping> curr = ret.get(id.get_streamId());
                      if (curr == null)
                          curr = new HashMap<>();
                      curr.put(otherComponentId, inputs.get(id));
                      ret.put(id.get_streamId(), curr);
                  }
              }
          }
          return ret;
      }
docs: Gets information about who is consuming the outputs of the specified component, and how.
  
  @return Map from stream id to component id to the Grouping used.