#NEWLINE# def union( self , s ) : #NEWLINE# #INDENT# check_deterministic ( s ) #NEWLINE# n = self . copy ( ) #NEWLINE# for elem in s : #NEWLINE# #INDENT# if ( elem not in n ) : #NEWLINE# #INDENT# n . add ( elem ) #NEWLINE# #UNINDENT# #UNINDENT# return n