Args:
            contract (Contract)
        Returns:
            list((Function), (list (Node)))

def detect_dangerous_timestamp(self, contract):
        """
        Args:
            contract (Contract)
        Returns:
            list((Function), (list (Node)))
        """
        ret = []
        for f in [f for f in contract.functions if f.contract == contract]:
            nodes = self.timestamp(f)
            if nodes:
                ret.append((f, nodes))
        return ret