def call(self, x, *args):
        """Apply _only_ the convert_token function of the current pipeline
        to the input. If the input is a list, a list with the results of
        applying the `convert_token` function to all input elements is
        returned.

        Arguments:
            x: The input to apply the convert_token function to.
            Positional arguments: Forwarded to the `convert_token` function
                of the current Pipeline.
        """
        if isinstance(x, list):
            return [self.convert_token(tok, *args) for tok in x]
        return self.convert_token(x, *args)