code: def _function_add_return_edge(self, return_from_addr, return_to_addr, function_addr):
          
  
          return_to_node = self._nodes.get(return_to_addr, None)
          if return_to_node is None:
              return_to_snippet = self._to_snippet(addr=return_to_addr, base_state=self._base_state)
              to_outside = False
          else:
              return_to_snippet = self._to_snippet(cfg_node=return_to_node)
              to_outside = return_to_node.function_address != function_addr
  
          self.kb.functions._add_return_from_call(function_addr, return_from_addr, return_to_snippet,
                                                  to_outside=to_outside)
docs: Generate CodeNodes for return_to_addr, add this node for function to
          function manager generating new edge
  
          :param int return_from_addr: target address
          :param int return_to_addr: target address
          :param int function_addr: address of function
          :return: None