def METHOD_NAME(name: str) -> Callable[[ModuleFunc], ModuleFunc]:
    """Decorator to register a function as status module.
    The decorated function must return a string that can be displayed as
    status. When calling :func:`evaluate`, any occurrence of ``name`` will be
    replaced by the return value of the decorated function.
    Args:
        name: Name of the module as set in the config file. Must start with '{'
            and end with '}' to allow differentiating modules from ordinary
            text.
    """
    def decorator(function: ModuleFunc) -> ModuleFunc:
        """Store function executable under module name."""
        if not name.startswith("{") or not name.endswith("}"):
            raise ValueError(
                f"Invalid name '{name}' for status module {function.__name__}"
            )
        _modules[name] = _Module(function)
        return function
    return decorator