pytorch

b777d790 - Convert Sampler back to lazily construction (#63646)

Convert Sampler back to lazily construction (#63646) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/63646 Fixes #63609 Test Plan: Imported from OSS Reviewed By: NivekT Differential Revision: D30451774 Pulled By: ejguan fbshipit-source-id: 550d77494326446d1a42b5da0559e0d384c47413