def forward(
        self,
        pixel_values: torch.Tensor,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
    ) -> BackboneOutput:
        """
        Returns:

        Examples:

        ```python
        >>> from transformers import AutoImageProcessor, AutoBackbone
        >>> import torch
        >>> from PIL import Image
        >>> import requests

        >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)

        >>> processor = AutoImageProcessor.from_pretrained("facebook/convnext-tiny-224")
        >>> model = AutoBackbone.from_pretrained("facebook/convnext-tiny-224")

        >>> inputs = processor(image, return_tensors="pt")
        >>> outputs = model(**inputs)
        ```"""
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )

        embedding_output = self.embeddings(pixel_values)

        outputs = self.encoder(
            embedding_output,
            output_hidden_states=True,
            return_dict=True,
        )

        hidden_states = outputs.hidden_states

        feature_maps = ()
        # we skip the stem
        for idx, (stage, hidden_state) in enumerate(zip(self.stage_names[1:], hidden_states[1:])):
            if stage in self.out_features:
                hidden_state = self.hidden_states_norms[stage](hidden_state)
                feature_maps += (hidden_state,)

        if not return_dict:
            output = (feature_maps,)
            if output_hidden_states:
                output += (outputs.hidden_states,)
            return output

        return BackboneOutput(
            feature_maps=feature_maps,
            hidden_states=outputs.hidden_states if output_hidden_states else None,
            attentions=None,
        )

        Returns:

        Examples:

        ```python
        >>> from transformers import AutoImageProcessor, AutoBackbone
        >>> import torch
        >>> from PIL import Image
        >>> import requests

        >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)

        >>> processor = AutoImageProcessor.from_pretrained("facebook/convnext-tiny-224")
        >>> model = AutoBackbone.from_pretrained("facebook/convnext-tiny-224")

        >>> inputs = processor(image, return_tensors="pt")
        >>> outputs = model(**inputs)
        ```
dpkd/transformers/src/transformers/models/convnext/modeling_convnext.py