human
Solve the following python programming problem given the following code:
def iter_extractor(node) : 
    @ calledWithBuiltinArgumentNamesDecorator 
    def wrapIterCreation(callable_arg, sentinel, source_ref) : 
        if (sentinel is None) : 
            return ExpressionBuiltinIter1 (value = callable_arg, source_ref = source_ref) 
else : 
            return ExpressionBuiltinIter2 (callable_arg = callable_arg, sentinel = sentinel, source_ref = source_ref) 
return BuiltinOptimization.extractBuiltinArgs (node = node, builtin_class = <MASK>, builtin_spec = BuiltinOptimization.builtin_iter_spec) 
    
    Given the code above, what is a proper replacement for <MASK>? Choose among: node
assistant
#Here is a proper replacement for <MASK>.
def wrapIterCreation(