@classmethod
def get_preferred_strategy(cls, strategy1, strategy2):
    """Get preferred strategy in case of multiple migrations being done at once.

        Chose strategy with higher priority - if two migrations are done at the same time one marked as IGNORE another
        as RETRY, we have to retry flow.

        :param strategy1: the first strategy to compare with
        :type strategy1: TaintedFlowStrategy
        :param strategy2: the second strategy to compare with
        :type strategy2: TaintedFlowStrategy
        :return: strategy with higher priority
        :rtype: TaintedFlowStrategy
        """
    return max(strategy1, strategy2)
