code: public Map<String, Collection<String>> toMap() {
          Map<String, Collection<String>> params = new HashMap<String, Collection<String>>();
          if (null != type) {
              ArrayList<String> valueList = new ArrayList<String>();
              valueList.add(type);
              params.put("type", valueList);
          }
          if (null != data) {
              ArrayList<String> valueList = new ArrayList<String>();
              valueList.add(data);
              params.put("data", valueList);
          }
  
          return params;
      }
docs: Returns the signal properties as a Map.