// This assumes that Grouping will always be used.
// Enabling grouping on the payload.
MRInputUserPayloadProto updatedPayload =
MRInputUserPayloadProto.newBuilder(protoPayload).setGroupingEnabled(true).build();
inputDescriptor.setUserPayload(UserPayload.create(updatedPayload.toByteString().asReadOnlyByteBuffer()));
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException(e);
}