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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 _function_add_node(self, cfg_node, function_addr):
 """ Adds node to function manager, converting address to CodeNode if possible :param CFGNode cfg_node: A CFGNode instance. :param int function_addr: Address of the current function. :return: None """

        snippet = self._to_snippet(cfg_node=cfg_node)
        self.kb.functions._add_node(function_addr, snippet)