added doctring to SchedulerType class (#32898)
* added doctring to SchedulerType class
* Remove trailing whitespace src/transformers/trainer_utils.py
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
* fixup
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Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
