def __call__(
        self,
        notes: Union[
            np.ndarray,
            List[pretty_midi.Note],
            List[List[pretty_midi.Note]],
        ],
        padding: Union[bool, str, PaddingStrategy] = False,
        truncation: Union[bool, str, TruncationStrategy] = None,
        max_length: Optional[int] = None,
        pad_to_multiple_of: Optional[int] = None,
        return_attention_mask: Optional[bool] = None,
        return_tensors: Optional[Union[str, TensorType]] = None,
        verbose: bool = True,
        **kwargs,
    ) -> BatchEncoding:
        r"""
        This is the `__call__` method for `Pop2PianoTokenizer`. It converts the midi notes to the transformer generated
        token ids.

        Args:
            notes (`numpy.ndarray` of shape `[batch_size, max_sequence_length, 4]` or `list` of `pretty_midi.Note` objects):
                This represents the midi notes.

                If `notes` is a `numpy.ndarray`:
                    - Each sequence must have 4 values, they are `onset idx`, `offset idx`, `pitch` and `velocity`.
                If `notes` is a `list` containing `pretty_midi.Note` objects:
                    - Each sequence must have 4 attributes, they are `start`, `end`, `pitch` and `velocity`.
            padding (`bool`, `str` or [`~file_utils.PaddingStrategy`], *optional*, defaults to `False`):
                Activates and controls padding. Accepts the following values:

                - `True` or `'longest'`: Pad to the longest sequence in the batch (or no padding if only a single
                  sequence if provided).
                - `'max_length'`: Pad to a maximum length specified with the argument `max_length` or to the maximum
                  acceptable input length for the model if that argument is not provided.
                - `False` or `'do_not_pad'` (default): No padding (i.e., can output a batch with sequences of different
                  lengths).
            truncation (`bool`, `str` or [`~tokenization_utils_base.TruncationStrategy`], *optional*, defaults to `False`):
                Activates and controls truncation. Accepts the following values:

                - `True` or `'longest_first'`: Truncate to a maximum length specified with the argument `max_length` or
                  to the maximum acceptable input length for the model if that argument is not provided. This will
                  truncate token by token, removing a token from the longest sequence in the pair if a pair of
                  sequences (or a batch of pairs) is provided.
                - `'only_first'`: Truncate to a maximum length specified with the argument `max_length` or to the
                  maximum acceptable input length for the model if that argument is not provided. This will only
                  truncate the first sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
                - `'only_second'`: Truncate to a maximum length specified with the argument `max_length` or to the
                  maximum acceptable input length for the model if that argument is not provided. This will only
                  truncate the second sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
                - `False` or `'do_not_truncate'` (default): No truncation (i.e., can output batch with sequence lengths
                  greater than the model maximum admissible input size).
            max_length (`int`, *optional*):
                Controls the maximum length to use by one of the truncation/padding parameters. If left unset or set to
                `None`, this will use the predefined model maximum length if a maximum length is required by one of the
                truncation/padding parameters. If the model has no specific maximum input length (like XLNet)
                truncation/padding to a maximum length will be deactivated.
            pad_to_multiple_of (`int`, *optional*):
                If set will pad the sequence to a multiple of the provided value. This is especially useful to enable
                the use of Tensor Cores on NVIDIA hardware with compute capability `>= 7.5` (Volta).
            return_attention_mask (`bool`, *optional*):
                Whether to return the attention mask. If left to the default, will return the attention mask according
                to the specific tokenizer's default, defined by the `return_outputs` attribute.

                [What are attention masks?](../glossary#attention-mask)
            return_tensors (`str` or [`~file_utils.TensorType`], *optional*):
                If set, will return tensors instead of list of python integers. Acceptable values are:

                - `'tf'`: Return TensorFlow `tf.constant` objects.
                - `'pt'`: Return PyTorch `torch.Tensor` objects.
                - `'np'`: Return Numpy `np.ndarray` objects.
            verbose (`bool`, *optional*, defaults to `True`):
                Whether or not to print more information and warnings.

        Returns:
            `BatchEncoding` containing the token_ids.
        """

        # check if it is batched or not
        # it is batched if its a list containing a list of `pretty_midi.Notes` where the outer list contains all the
        # batches and the inner list contains all Notes for a single batch. Otherwise if np.ndarray is passed it will be
        # considered batched if it has shape of `[batch_size, seqence_length, 4]` or ndim=3.
        is_batched = notes.ndim == 3 if isinstance(notes, np.ndarray) else isinstance(notes[0], list)

        # get the truncation and padding strategy
        padding_strategy, truncation_strategy, max_length, kwargs = self._get_padding_truncation_strategies(
            padding=padding,
            truncation=truncation,
            max_length=max_length,
            pad_to_multiple_of=pad_to_multiple_of,
            verbose=verbose,
            **kwargs,
        )

        if is_batched:
            # If the user has not explicitly mentioned `return_attention_mask` as False, we change it to True
            return_attention_mask = True if return_attention_mask is None else return_attention_mask
            token_ids = self.batch_encode_plus(
                notes=notes,
                truncation_strategy=truncation_strategy,
                max_length=max_length,
                **kwargs,
            )
        else:
            token_ids = self.encode_plus(
                notes=notes,
                truncation_strategy=truncation_strategy,
                max_length=max_length,
                **kwargs,
            )

        # since we already have truncated sequnences we are just left to do padding
        token_ids = self.pad(
            token_ids,
            padding=padding_strategy,
            max_length=max_length,
            pad_to_multiple_of=pad_to_multiple_of,
            return_attention_mask=return_attention_mask,
            return_tensors=return_tensors,
            verbose=verbose,
        )

        return token_ids

        This is the `__call__` method for `Pop2PianoTokenizer`. It converts the midi notes to the transformer generated
        token ids.

        Args:
            notes (`numpy.ndarray` of shape `[batch_size, max_sequence_length, 4]` or `list` of `pretty_midi.Note` objects):
                This represents the midi notes.

                If `notes` is a `numpy.ndarray`:
                    - Each sequence must have 4 values, they are `onset idx`, `offset idx`, `pitch` and `velocity`.
                If `notes` is a `list` containing `pretty_midi.Note` objects:
                    - Each sequence must have 4 attributes, they are `start`, `end`, `pitch` and `velocity`.
            padding (`bool`, `str` or [`~file_utils.PaddingStrategy`], *optional*, defaults to `False`):
                Activates and controls padding. Accepts the following values:

                - `True` or `'longest'`: Pad to the longest sequence in the batch (or no padding if only a single
                  sequence if provided).
                - `'max_length'`: Pad to a maximum length specified with the argument `max_length` or to the maximum
                  acceptable input length for the model if that argument is not provided.
                - `False` or `'do_not_pad'` (default): No padding (i.e., can output a batch with sequences of different
                  lengths).
            truncation (`bool`, `str` or [`~tokenization_utils_base.TruncationStrategy`], *optional*, defaults to `False`):
                Activates and controls truncation. Accepts the following values:

                - `True` or `'longest_first'`: Truncate to a maximum length specified with the argument `max_length` or
                  to the maximum acceptable input length for the model if that argument is not provided. This will
                  truncate token by token, removing a token from the longest sequence in the pair if a pair of
                  sequences (or a batch of pairs) is provided.
                - `'only_first'`: Truncate to a maximum length specified with the argument `max_length` or to the
                  maximum acceptable input length for the model if that argument is not provided. This will only
                  truncate the first sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
                - `'only_second'`: Truncate to a maximum length specified with the argument `max_length` or to the
                  maximum acceptable input length for the model if that argument is not provided. This will only
                  truncate the second sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
                - `False` or `'do_not_truncate'` (default): No truncation (i.e., can output batch with sequence lengths
                  greater than the model maximum admissible input size).
            max_length (`int`, *optional*):
                Controls the maximum length to use by one of the truncation/padding parameters. If left unset or set to
                `None`, this will use the predefined model maximum length if a maximum length is required by one of the
                truncation/padding parameters. If the model has no specific maximum input length (like XLNet)
                truncation/padding to a maximum length will be deactivated.
            pad_to_multiple_of (`int`, *optional*):
                If set will pad the sequence to a multiple of the provided value. This is especially useful to enable
                the use of Tensor Cores on NVIDIA hardware with compute capability `>= 7.5` (Volta).
            return_attention_mask (`bool`, *optional*):
                Whether to return the attention mask. If left to the default, will return the attention mask according
                to the specific tokenizer's default, defined by the `return_outputs` attribute.

                [What are attention masks?](../glossary#attention-mask)
            return_tensors (`str` or [`~file_utils.TensorType`], *optional*):
                If set, will return tensors instead of list of python integers. Acceptable values are:

                - `'tf'`: Return TensorFlow `tf.constant` objects.
                - `'pt'`: Return PyTorch `torch.Tensor` objects.
                - `'np'`: Return Numpy `np.ndarray` objects.
            verbose (`bool`, *optional*, defaults to `True`):
                Whether or not to print more information and warnings.

        Returns:
            `BatchEncoding` containing the token_ids.
        
dpkd/transformers/src/transformers/models/pop2piano/tokenization_pop2piano.py