code: public Future<Map<Long, List<LeagueList>>> getLeagues(long... summoners) {
          return new ApiFuture<>(() -> handler.getLeagues(summoners));
      }
docs: Get a listing of leagues for the specified summoners
  @param summoners The ids of the summoners
  @return A list of leagues
  @see <a href=https://developer.riotgames.com/api/methods#!/593/1862>Official API documentation</a>