def _format_themes(self, themes: str, test_breadth: int) -> list:
        """
        Formats the themes into a python list using an LLM.

        Args:
            themes (str): The themes to be formatted.

        Returns:
            list: A list of formatted themes.
        """
        theme_format = [f"theme {i + 1}" for i in range(test_breadth)]
        response = self.app_callable(
            f"Take the following themes, and turn them into a python list of the exact format: {theme_format}.\n\n"
            f"Themes: {themes}\n\n"
            "Python list:"
        )
        test_categories = (
            response.response if hasattr(response, "response") else response
        )
        # Attempt to evaluate the string as a Python literal.
        try:
            test_categories = literal_eval(test_categories)
        except SyntaxError as e:
            raise ValueError(
                f"Failed to parse themes string: {test_categories}"
            ) from e
        return test_categories

        Formats the themes into a python list using an LLM.

        Args:
            themes (str): The themes to be formatted.

        Returns:
            list: A list of formatted themes.
        
src/benchmark/trulens/benchmark/generate/generate_test_set.py