#NEWLINE# def __getitem__( self , item ) : #NEWLINE# #INDENT# assert isinstance ( item , ( list , tuple , _Attribute , str ) ) #NEWLINE# if isinstance ( item , ( list , tuple ) ) : #NEWLINE# #INDENT# self . children . extend ( item ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# self . children . append ( item ) #NEWLINE# #UNINDENT# return self