Warpping model.generate before exporting into tensorflow savedmodel format
# 🚀 Feature request

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I had been using BART model and there i can use model.generate if i am working with checkpoints. However model.generate is not exported when i export the model as savedmodel ".pb" format. So is there a way to wrap model.generate while exporting savedmodel, so that it allows using beam search and generation of summary_ids to generate summary

## Motivation

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Will allow summary generation with  savedmodel format for BART like models that uses  model.generate
Related to https://github.com/huggingface/transformers/issues/5443 which has been marked closed.

## Your contribution

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