#NEWLINE# def __init__( self , data = None ) : #NEWLINE# #INDENT# self . data = set ( ) #NEWLINE# def _remove( item , selfref = ref ( self ) ) : #NEWLINE# #INDENT# self = selfref ( ) #NEWLINE# if ( self is not None ) : #NEWLINE# #INDENT# if self . _iterating : #NEWLINE# #INDENT# self . _pending_removals . append ( item ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# self . data . discard ( item ) #NEWLINE# #UNINDENT# #UNINDENT# #UNINDENT# self . _remove = _remove #NEWLINE# self . _pending_removals = [ ] #NEWLINE# self . _iterating = set ( ) #NEWLINE# if ( data is not None ) : #NEWLINE# #INDENT# self . update ( data )