LayoutLMv2Model can not be imported from transformers
Hi @NielsRogge 

Getting error when calling LayoutLMv2Model class with `from transformers import LayoutLMv2Model` as instructed at the [official documentation](https://huggingface.co/docs/transformers/model_doc/layoutxlm)

`ImportError: cannot import name 'LayoutLMv2Model' from transformers (unknown location)`


It should be under **transformers/models/layoutlmv2/modeling_layoutlmv2.py**

I have `transformers` version: 4.5.1:


The issue has been resolved. LayoutLMv2Model class exist in `transformers=4.16.2` version<|||||>what about installing from the source 

```
!git clone https://github.com/huggingface/transformers.git
%cd transformers
!pip install -e .
```

i tried to run run_mlm.py but got many errors in importing the modules

