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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def enter_node(self, ir_node):
 """ Enter the given element; keeps track of `cdata`; subclasses may extend by overriding """

        this_is_cdata = (isinstance(ir_node, Element)
                         and ir_node.name in self.cdata_elements)
        self.state['is_cdata'] = bool(self.state.get('is_cdata')) or this_is_cdata