def parse_function_type_comment(type_comment: str) -> Optional[FunctionType]:
    """Given a correct type comment, obtain a FunctionType object"""
    if _ast_py3 is None:
        return None

    func_type = _ast_py3.parse(type_comment, "<type_comment>", "func_type")
    return FunctionType(argtypes=func_type.argtypes, returns=func_type.returns)
Given a correct type comment, obtain a FunctionType object