`INSTALLATION.md` specifies that TF + Keras 2.6 should be installed. Keras 2.6 does not have yet the `optimizers.legacy` module although [this commit](https://github.com/google-research/deeplab2/commit/fe8ec061eb7dec8c81e52a5b17a79fdbf63bddd2) uses it, which creates a runtime error. Either the required TF + Keras version should be updated or this commit reverted, I guess?
INSTALLATION.mdspecifies that TF + Keras 2.6 should be installed.Keras 2.6 does not have yet the
optimizers.legacymodule although this commit uses it, which creates a runtime error.Either the required TF + Keras version should be updated or this commit reverted, I guess?