protected <T extends RemoteOperation> List<T> fetchType(
    final ArrayListMultimap<Class<?>, RemoteOperation> requestByType, final Class<T> type) {
    return (List<T>) requestByType.removeAll(type);
  }
Account of what procedures are running on remote node.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/RemoteProcedureDispatcher.java