(self, sim_file)
Look up the path of a SimFile in the mountpoint

        :param sim_file:        A SimFile object needs to be looked up
        :return:                A string representing the path of the file in the mountpoint
                                Or None if the SimFile does not exist in the mountpoint
Look up the path of a SimFile in the mountpoint
Look up the path of a SimFile in the mountpoint
def lookup(self, sim_file):
        """
        Look up the path of a SimFile in the mountpoint

        :param sim_file:        A SimFile object needs to be looked up
        :return:                A string representing the path of the file in the mountpoint
                                Or None if the SimFile does not exist in the mountpoint
        """
        raise NotImplementedError
def lookup ( self , sim_file ) : raise NotImplementedError