@Override
  public ListNamespacesResponse listNamespaces(RpcController controller,
    ListNamespacesRequest request) throws ServiceException {
    try {
      return ListNamespacesResponse.newBuilder().addAllNamespaceName(server.listNamespaces())
        .build();
    } catch (IOException e) {
      throw new ServiceException(e);
    }
  }
List the currently available/stored snapshots. Any in-progress snapshots are ignored
hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java