Supporting non-vision models

Hi,
could you explain how to use this for non-vision models?
Trying to apply this to an audio model I am getting an error because `get_previous_layer` never finds a `Conv2d` or a `BatchNorm2d` and hence, after recursing through all the modules, just returns None, which then fails at `re.sub`.

Could you explain the logic behind "going back to the previous layer of exactly this type"?

the immediate earlier layers are: (add, causing the search) -> [transpose] -> gelu -> transpose -> layer_norm -> transpose -> conv1d -> ...

which layer would you expect to find here? Are you looking for the last layer that learns anything (which would be layer norm) or with actual learnable parameters (then it's conv1d)

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there is a second case where this happens where the chain is: (add, causing the search) -> [dropout] -> linear -> layer_norm -> transpose -> gelu -> transpose -> layer_norm -> transpose -> conv1d -> ...

again, please help me out which layer should be found. I would guess the linear layer?

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on a side note: instead of deep recursion, checking the whole list each time, building a tree or doubly-linked-list-like structure seems more appropriate (and easier to debug)

Start by tracing get_previous_layer to the re.sub call that receives None, then compare its Conv2d/BatchNorm2d assumptions with the reported Conv1d, Linear, LayerNorm, GELU, transpose, dropout, and add chains. Done means documenting which predecessor should be selected for non-vision models and defining behavior when no supported layer is found.

Written by the indexing model from the issue text.