def __call__(self):
        return self.pa_type

    def str2int(self, values: Union[str, Iterable]) -> Union[int, Iterable]:
        """Conversion class name `string` => `integer`.

        Example:

        ```py
        >>> from datasets import load_dataset
        >>> ds = load_dataset("rotten_tomatoes", split="train")
        >>> ds.features["label"].str2int('neg')
        0
        ```
        """
        if not isinstance(values, str) and not isinstance(values, Iterable):
            raise ValueError(
                f"Values {values} should be a string or an Iterable (list, numpy array, pytorch, tensorflow tensors)"
            )
        return_list = True
        if isinstance(values, str):
            values = [values]
            return_list = False

        output = [self._strval2int(value) for value in values]
        return output if return_list else output[0]