Support user defined dicts (#143548)
Summary:
X-link: https://github.com/pytorch/pytorch/pull/143548
Approved by: https://github.com/yanboliang, https://github.com/jansel, https://github.com/williamwen42
Reviewed By: huydhn
Differential Revision: D67554535
Pulled By: anijain2305
fbshipit-source-id: 04dd5f1571a19e39672739428e4b1e3e9ed04492
