def METHOD_NAME(  # noqa: D
    self, node: JoinAggregatedMeasuresByGroupByColumnsNode
) -> DefaultCost:
    parent_costs = [x.accept(self) for x in node.parent_nodes]
    # This node does N-1 joins to link its N parents together
    num_joins = len(node.parent_nodes) - 1
    node_cost = DefaultCost(num_joins=num_joins)
    return DefaultCost.sum(parent_costs + [node_cost])