ShutdownPrepareRequest.Builder builder = ShutdownPrepareRequest.newBuilder()
.setSenderSite(this.catalog_site.getId());
// Pack the error into a SerializableException
if (error != null) {
SerializableException sError = new SerializableException(error);
ByteBuffer buffer = sError.serializeToBuffer();
buffer.rewind();
builder.setError(ByteString.copyFrom(buffer));
if (debug.val)
LOG.debug("Serializing error message in shutdown request");
}