def char_to_token(
        self, batch_or_char_index: int, char_index: Optional[int] = None, sequence_index: int = 0
    ) -> int:
        """
        Get the index of the token in the encoded output comprising a character in the original string for a sequence
        of the batch.

        Can be called as:

        - `self.char_to_token(char_index)` if batch size is 1
        - `self.char_to_token(batch_index, char_index)` if batch size is greater or equal to 1

        This method is particularly suited when the input sequences are provided as pre-tokenized sequences (i.e. words
        are defined by the user). In this case it allows to easily associate encoded tokens with provided tokenized
        words.

        Args:
            batch_or_char_index (`int`):
                Index of the sequence in the batch. If the batch only comprise one sequence, this can be the index of
                the word in the sequence
            char_index (`int`, *optional*):
                If a batch index is provided in *batch_or_token_index*, this can be the index of the word in the
                sequence.
            sequence_index (`int`, *optional*, defaults to 0):
                If pair of sequences are encoded in the batch this can be used to specify which sequence in the pair (0
                or 1) the provided character index belongs to.


        Returns:
            `int`: Index of the token.
        """

        if not self._encodings:
            raise ValueError("char_to_token() is not available when using Python based tokenizers")
        if char_index is not None:
            batch_index = batch_or_char_index
        else:
            batch_index = 0
            char_index = batch_or_char_index
        return self._encodings[batch_index].char_to_token(char_index, sequence_index)

        Get the index of the token in the encoded output comprising a character in the original string for a sequence
        of the batch.

        Can be called as:

        - `self.char_to_token(char_index)` if batch size is 1
        - `self.char_to_token(batch_index, char_index)` if batch size is greater or equal to 1

        This method is particularly suited when the input sequences are provided as pre-tokenized sequences (i.e. words
        are defined by the user). In this case it allows to easily associate encoded tokens with provided tokenized
        words.

        Args:
            batch_or_char_index (`int`):
                Index of the sequence in the batch. If the batch only comprise one sequence, this can be the index of
                the word in the sequence
            char_index (`int`, *optional*):
                If a batch index is provided in *batch_or_token_index*, this can be the index of the word in the
                sequence.
            sequence_index (`int`, *optional*, defaults to 0):
                If pair of sequences are encoded in the batch this can be used to specify which sequence in the pair (0
                or 1) the provided character index belongs to.


        Returns:
            `int`: Index of the token.
        
dpkd/transformers/src/transformers/tokenization_utils_base.py