#NEWLINE# def add_pop_key_list( self , key ) : #NEWLINE# #INDENT# '\n        Add a external file unit number to a list that will be used to remove\n        model output (typically binary) files from ext_unit_dict.\n\n        Parameters\n        ----------\n        key : int\n            file unit number\n\n        Returns\n        -------\n\n        Examples\n        --------\n\n        ' #NEWLINE# if ( self not in self . pop_key_list ) : #NEWLINE# #INDENT# self . pop_key_list . append ( key )