Update torch.Tensor.is_set_to documentation (#43052)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/30350
Preview:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43052
Reviewed By: mrshenli
Differential Revision: D23173066
Pulled By: suraj813
fbshipit-source-id: d90a11490739068ea448d975548a71e07180bd77
