docs: public List<RosterGroup> getGroups() {
          List<RosterGroup> results = new ArrayList<>();
          // Loop through all roster groups and find the ones that contain this
          // entry. This algorithm should be fine
          for (RosterGroup group : roster.getGroups()) {
              if (group.contains(this)) {
                  results.add(group);
              }
          }
          return results;
      }