def telephone(self, mask: str = '', placeholder: str = '#') -> str:
        """Generate a random phone number.

        :param mask: Mask for formatting number.
        :param placeholder: A placeholder for a mask (default is #).
        :return: Phone number.

        :Example:
            +7-(963)-409-11-22.
        """
        if not mask:
            code = self.random.choice(CALLING_CODES)
            default = '{}-(###)-###-####'.format(code)
            masks = self._data.get('telephone_fmt', [default])
            mask = self.random.choice(masks)

        return self.random.custom_code(mask=mask, digit=placeholder)
Generate a random phone number.

        :param mask: Mask for formatting number.
        :param placeholder: A placeholder for a mask (default is #).
        :return: Phone number.

        :Example:
            +7-(963)-409-11-22.