code: public void setChannels(List<String> channels) {
          if (channels != null && !channels.isEmpty()) {
              if (!isPull()) {
                  Log.w(Log.TAG_SYNC, "filterChannels can only be set in pull replications");
                  return;
              }
              setFilter(BY_CHANNEL_FILTER_NAME);
              Map<String, Object> filterParams = new HashMap<String, Object>();
              filterParams.put(CHANNELS_QUERY_PARAM, TextUtils.join(",", channels));
              setFilterParams(filterParams);
          } else if (BY_CHANNEL_FILTER_NAME.equals(getFilter())) {
              setFilter(null);
              setFilterParams(null);
          }
      }
docs: For javadocs, see Replication object