Get a random file name with some extension.

        :param file_type: Enum object FileType
        :return: File name.

        :Example:
            legislative.txt

def file_name(self, file_type: Optional[FileType] = None) -> str:
        """Get a random file name with some extension.

        :param file_type: Enum object FileType
        :return: File name.

        :Example:
            legislative.txt
        """
        name = self.__text.word()
        ext = self.extension(file_type)

        return '{name}{ext}'.format(
            name=self.__sub(name),
            ext=ext,
        )