def walk(self, node, condition=None):
if not isinstance(node, Node):<EOL><INDENT>raise TypeError('<STR_LIT>')<EOL><DEDENT>for child in node:<EOL><INDENT>yield child<EOL>for subchild in self.walk(child, condition):<EOL><INDENT>yield subchild<EOL><DEDENT><DEDENT>
Simply walk through the entire node; condition argument is
ignored.