Learning rate finder for the trainer 
Hi,

is it possible to integrate a learning rate finder with the trainer api?
Something like this:
https://github.com/davidtvs/pytorch-lr-finder

It's probably has been done before, but couldn't find it yet.
The LR finder does not give reliable results for Transformers models (usually indicates one in the 1e-3 when the actual best value is in the 1e-5 range). That's why we don't have support for it.<|||||>@sgugger thanks for the explanation. Any other best practices?