@Override
  public Map<ServerName, Boolean> compactionSwitch(boolean switchState,
    List<String> serverNamesList) throws IOException {
    return get(admin.compactionSwitch(switchState, serverNamesList));
  }
The {@link Admin} implementation which is based on an {@link AsyncAdmin}.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/AdminOverAsyncAdmin.java