def visit(self, node, *args):
        "Recursively validate node and all of its children."
        fn = getattr(self, 'visit' + classname(node))
        if DEBUG: self.trace(node)
        fn(node, *args)
        for child in node.getChildNodes():
            self.visit(child, *args)
Recursively validate node and all of its children.
recipes/Python/496746_Restricted_safe_eval/recipe-496746.py