    def get_extended_attention_mask(self, attention_mask, input_shape, device):
        """This is borrowed from `modeling_utils.py` with the support of
        multi-layer attention masks.
        The second dim is expected to be number of layers.
        See `MMAttentionMaskProcessor`.
        Makes broadcastable attention and causal masks so that future
        and masked tokens are ignored.

        Arguments:
            attention_mask (:obj:`torch.Tensor`):
                Mask with ones indicating tokens to attend to,
                zeros for tokens to ignore.
            input_shape (:obj:`Tuple[int]`):
                The shape of the input to the model.
            device: (:obj:`torch.device`):
                The device of the input to the model.

        Returns:
            :obj:`torch.Tensor` The extended attention mask, \
                with a the same dtype as :obj:`attention_mask.dtype`.
        """
        # We can provide a self-attention mask of dimensions
        # [batch_size, from_seq_length, to_seq_length]
        # ourselves in which case we just need to make it broadcastable
        # to all heads.
        if attention_mask.dim() == 4:
            extended_attention_mask = attention_mask[:, :, None, :, :]
            extended_attention_mask = extended_attention_mask.to(
                dtype=self.dtype
            )  # fp16 compatibility
            extended_attention_mask = (1.0 - extended_attention_mask) \
                * -10000.0
            return extended_attention_mask
        else:
            return super().get_extended_attention_mask(
                attention_mask, input_shape, device
            )
This is borrowed from `modeling_utils.py` with the support of
multi-layer attention masks.
The second dim is expected to be number of layers.
See `MMAttentionMaskProcessor`.
Makes broadcastable attention and causal masks so that future
and masked tokens are ignored.

Arguments:
attention_mask (:obj:`torch.Tensor`):
Mask with ones indicating tokens to attend to,
zeros for tokens to ignore.
input_shape (:obj:`Tuple[int]`):
The shape of the input to the model.
device: (:obj:`torch.device`):
The device of the input to the model.

Returns:
:obj:`torch.Tensor` The extended attention mask, \
with a the same dtype as :obj:`attention_mask.dtype`.
examples/MMPT/mmpt/models/transformermodel.py