Use QualifiedName for classes (#19575)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19575
ghimport-source-id: eaed1d9d66672aadfe893e62a3a811da8ac7d966
Differential Revision: D15035281
Reviewed By: shannonzhu
Pulled By: suo
fbshipit-source-id: 7bac5e5f9223af77268bc03e08b37450a6840dbe
