src/transformers/modeling_tf_utils.py/TFPreTrainedModel/prune_heads
class TFPreTrainedModel:    def prune_heads(self, heads_to_prune):
        """
        Prunes heads of the base model.

        Arguments:
            heads_to_prune (:obj:`Dict[int, List[int]]`):
                Dictionary with keys being selected layer indices (:obj:`int`) and associated values being the list of
                heads to prune in said layer (list of :obj:`int`). For instance {1: [0, 2], 2: [2, 3]} will prune heads
                0 and 2 on layer 1 and heads 2 and 3 on layer 2.
        """
        raise NotImplementedError