code: public ByteBuffer createRemote(CounterId id, long clock, long count)
      {
          ContextState state = ContextState.allocate(0, 0, 1);
          state.writeRemote(id, clock, count);
          return state.context;
      }
docs: Creates a counter context with a single remote shard.
  For use by tests of compatibility with pre-2.1 counters only.