code: public Groups getGroups(String userId, EnumSet<JinxConstants.GroupExtras> extras) throws JinxException {
      JinxUtils.validateParams(userId);
      Map<String, String> params = new TreeMap<>();
      params.put("method", "flickr.people.getGroups");
      params.put("user_id", userId);
      if (!JinxUtils.isNullOrEmpty(extras)) {
        params.put("extras", JinxUtils.buildCommaDelimitedList(extras));
      }
      return jinx.flickrGet(params, Groups.class);
    }
docs: Returns the list of groups a user is a member of.
  <br>
  This method requires authentication with 'read' permission.
  <br>
  Flickr does not return pagination information for this call. The returned object will not have any values set for
  pagination, and the the getPage(), getPages(), getPerPage(), or getTotal() methods will return null.
  
  @param userId (Required) The user id of the user to fetch groups for.
  @param extras extra information to fetch for each returned record.
  @return object with information about the groups the user is a member of.
  @throws JinxException if required parameters are missing, or if there are any errors.
  @see <a href="https://www.flickr.com/services/api/flickr.people.getGroups.html">flickr.people.getGroups</a>