pytorch

a3f0d988 - Revert D17349760: Change schedulers to chainable form

Revert D17349760: Change schedulers to chainable form Test Plan: revert-hammer Differential Revision: D17349760 Original commit changeset: 0a6ac01e2a6b fbshipit-source-id: 41c2c136215dabc26cad5098a08eff2a2a29b715