What is the most general way to find out all the convolutional layers in a PyTorch saved model?

In trying to work on a project, in which I would like to ensure that anyone can use any CNN model they like, I had the following question :

How can I specifically search for Convolutional layers in the loaded model ? Ideally it would be best to be able to find all the keys in the state_dict which correspond to convolutional layers.

In an even more general version of the question one may want to identify all the keys corresponding to a particular type of layer such as BatchNormalization or Pooling.

What is the recommended and efficient way of doing that ?