code: public void leave(String groupId, Boolean deletePhotos) throws FlickrException {
          Map<String, Object> parameters = new HashMap<String, Object>();
          parameters.put("method", METHOD_LEAVE);
          parameters.put("group_id", groupId);
          parameters.put("delete_photos", deletePhotos);
  
          Response response = transportAPI.post(transportAPI.getPath(), parameters, apiKey, sharedSecret);
          if (response.isError()) {
              throw new FlickrException(response.getErrorCode(), response.getErrorMessage());
          }
      }
docs: Leave a group.
  
  @see <a href="http://www.flickr.com/services/api/flickr.groups.leave.html">lickr.groups.leave</a> for a description of the various behaviors possible
  when a user leaves a group.
  
  @param groupId
  - the id of the group to leave
  @param deletePhotos
  - delete photos by this user from group