As an added bonus, note that the reduce function can be the same because it just sums up grouped keys!
作为一个额外的奖励，请注意reduce函数可以是相同的，因为它只汇总已分组的键！
When the Renderer module is used as the default rendering engine, it is recommended that an additional module is added to the configuration file to facilitate this function.
当 Renderer 模块用作默认的表示引擎时，建议添加一个附加的模块到配置文件以促进该功能。
Once the marker is added to the map as an overlay, the drawLine function is called.
将这个标记作为叠加层添加到地图上之后，调用drawLine函数。
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