我有一个projects集合，其中包含如下文档:{"_id":ObjectId("589eff3fee3d13019843f55a"),"name":"ProjectA","desc":"test","numofvms":0,"templates":[{"_id":ObjectId("589e4c14ee3d131bac8b403c")},{"_id":ObjectId("589e4c1dee3d131bac8b403d")}],"nodes":[{"_id":ObjectId("589eff8f2bb59057c3f9b89d"),"name":"NodeA"},{"_id":Obj