@Override
  public ModifyNamespaceResponse modifyNamespace(RpcController controller,
    ModifyNamespaceRequest request) throws ServiceException {
    try {
      long procId =
        server.modifyNamespace(ProtobufUtil.toNamespaceDescriptor(request.getNamespaceDescriptor()),
          request.getNonceGroup(), request.getNonce());
      return ModifyNamespaceResponse.newBuilder().setProcId(procId).build();
    } catch (IOException e) {
      throw new ServiceException(e);
    }
  }
Checks if the specified snapshot is done.
@return true if the snapshot is in file system ready to use, false if the snapshot is in the
        process of completing
@throws ServiceException wrapping UnknownSnapshotException if invalid snapshot, or a wrapped
                         HBaseSnapshotException with progress failure reason.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java