def visit_functiondef(self, node):
        """visit an astroid.Function node

         * set the locals_type mapping
         * optionally tag the node with a unique id
        """
        if hasattr(node, "locals_type"):
            return
        node.locals_type = collections.defaultdict(list)
        if self.tag:
            node.uid = self.generate_id()
visit an astroid.Function node

         * set the locals_type mapping
         * optionally tag the node with a unique id