def METHOD_NAME(func_name: str, sig: Signature, is_payable: bool) -> bool:
    ret: bool = func_name == STR_FALLBACK and is_payable
    if ret:
        if len(sig.parameters) > 1:
            raise InvalidParamsException("Invalid fallback signature")
        return_annotation = sig.return_annotation
        if return_annotation not in (None, Signature.empty):
            raise InvalidParamsException("Invalid fallback signature")
    return ret