How to input hidden state vectors from GPT2Model directly into mc_head of the GPT2DoubleHeads Model?
Hello,

I want to perform the following task:

**1.** _Feed in a text sequence to a GPT2Model (the GPT-2 model without output head);_

**2.** _Extract the hidden state vectors of the text sequence that are generated at each layer of the GPT2Model;_

**3.** _Input the hidden state vectors from each layer of the GPT2Model directly into the mc_head of the GPT2DoubleHeadsModel, and calculate the **mc_loss** that results from inputting the hidden state vectors._


I know that the code below can be used to input hidden state vectors into each individual layer of a HuggingFace GPT-2 model, but I am not sure if similar task can be done on the mc_head of the GPT2DoubleHeadsModel:

```python
model.transformer.h[i](embed)
```

My questions is:
 Is there anyway that I can input the hidden state vectors from each layer of the GPT2Model directly into the multiple choice head of the GPT2DoubleHeadsModel, and extract the **mc_loss** that results from it (i.e. is there any way that I can perform the task **3**)?

Thank you,