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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def list_helper(self,k,pak,attr,col):
 """ helper to setup list multiplier parameters for a given k, pak, attr set. Parameters k : int or iterable of int the zero-based stress period indices pak : flopy.PakBase= the MODFLOW package attr : MfList the MfList instance col : str the column name in the MfList recarray to parameterize """

        # special case for horrible HFB6 exception
        # if type(pak) == flopy.modflow.mfhfb.ModflowHfb:
        #     filename = pak.file_name[0]
        # else:
        filename = attr.get_filename(k)
        filename_model = os.path.join(self.m.external_path,filename)
        shutil.copy2(os.path.join(self.m.model_ws,filename_model),
                     os.path.join(self.m.model_ws,self.list_org,filename))
        return filename_model