docs: public void putCustomQueryParameter(String name, String value) {
          if (customQueryParameters == null) {
              customQueryParameters = new HashMap<String, List<String>>();
          }
          List<String> paramList = customQueryParameters.get(name);
          if (paramList == null) {
              paramList = new LinkedList<String>();
              customQueryParameters.put(name, paramList);
          }
          paramList.add(value);
      }