def forward(
        self,
        input_ids: Optional[torch.Tensor] = None,
        attention_mask: Optional[torch.Tensor] = None,
        decoder_input_ids: Optional[torch.Tensor] = None,
        decoder_attention_mask: Optional[torch.BoolTensor] = None,
        head_mask: Optional[torch.Tensor] = None,
        decoder_head_mask: Optional[torch.Tensor] = None,
        cross_attn_head_mask: Optional[torch.Tensor] = None,
        encoder_outputs: Optional[Tuple] = None,
        past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None,
        inputs_embeds: Optional[torch.Tensor] = None,
        decoder_inputs_embeds: Optional[torch.Tensor] = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
    ) -> Union[Tuple, ProphetNetSeq2SeqModelOutput]:
        r"""
        Returns:

        Example:

        ```python
        >>> from transformers import AutoTokenizer, ProphetNetModel

        >>> tokenizer = AutoTokenizer.from_pretrained("microsoft/prophetnet-large-uncased")
        >>> model = ProphetNetModel.from_pretrained("microsoft/prophetnet-large-uncased")

        >>> input_ids = tokenizer(
        ...     "Studies have been shown that owning a dog is good for you", return_tensors="pt"
        ... ).input_ids  # Batch size 1
        >>> decoder_input_ids = tokenizer("Studies show that", return_tensors="pt").input_ids  # Batch size 1
        >>> outputs = model(input_ids=input_ids, decoder_input_ids=decoder_input_ids)

        >>> last_hidden_states = outputs.last_hidden_state  # main stream hidden states
        >>> last_hidden_states_ngram = outputs.last_hidden_state_ngram  # predict hidden states
        ```"""
        use_cache = use_cache if use_cache is not None else self.config.use_cache
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        if encoder_outputs is None:
            encoder_outputs = self.encoder(
                input_ids=input_ids,
                attention_mask=attention_mask,
                head_mask=head_mask,
                inputs_embeds=inputs_embeds,
                output_attentions=output_attentions,
                output_hidden_states=output_hidden_states,
                return_dict=return_dict,
            )

        # decoder outputs consists of (dec_features, past_key_values, dec_hidden, dec_attn)
        decoder_outputs = self.decoder(
            input_ids=decoder_input_ids,
            attention_mask=decoder_attention_mask,
            encoder_hidden_states=encoder_outputs[0],
            encoder_attention_mask=attention_mask,
            head_mask=decoder_head_mask,
            cross_attn_head_mask=cross_attn_head_mask,
            past_key_values=past_key_values,
            inputs_embeds=decoder_inputs_embeds,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            use_cache=use_cache,
            return_dict=return_dict,
        )

        if not return_dict:
            return decoder_outputs + encoder_outputs
        return ProphetNetSeq2SeqModelOutput(
            last_hidden_state=decoder_outputs.last_hidden_state,
            last_hidden_state_ngram=decoder_outputs.last_hidden_state_ngram,
            past_key_values=decoder_outputs.past_key_values,
            decoder_hidden_states=decoder_outputs.hidden_states,
            decoder_ngram_hidden_states=decoder_outputs.hidden_states_ngram,
            decoder_attentions=decoder_outputs.attentions,
            decoder_ngram_attentions=decoder_outputs.ngram_attentions,
            cross_attentions=decoder_outputs.cross_attentions,
            encoder_last_hidden_state=encoder_outputs.last_hidden_state,
            encoder_hidden_states=encoder_outputs.hidden_states,
            encoder_attentions=encoder_outputs.attentions,
        )

        Returns:

        Example:

        ```python
        >>> from transformers import AutoTokenizer, ProphetNetModel

        >>> tokenizer = AutoTokenizer.from_pretrained("microsoft/prophetnet-large-uncased")
        >>> model = ProphetNetModel.from_pretrained("microsoft/prophetnet-large-uncased")

        >>> input_ids = tokenizer(
        ...     "Studies have been shown that owning a dog is good for you", return_tensors="pt"
        ... ).input_ids  # Batch size 1
        >>> decoder_input_ids = tokenizer("Studies show that", return_tensors="pt").input_ids  # Batch size 1
        >>> outputs = model(input_ids=input_ids, decoder_input_ids=decoder_input_ids)

        >>> last_hidden_states = outputs.last_hidden_state  # main stream hidden states
        >>> last_hidden_states_ngram = outputs.last_hidden_state_ngram  # predict hidden states
        ```
dpkd/transformers/src/transformers/models/prophetnet/modeling_prophetnet.py