+ """
+ Judge whether stat1 and stat2 both have same key, if both have same key,
+ call the aggregate fuction, else use the stat1's value
+ """
+ newstat = dict()
+ for keys in stat1.keys():
+ if keys in stat2 and isinstance(stat1[keys], dict):
+ newstat[keys] = aggregate(stat1[keys], stat2[keys])
+ else:
+ newstat[keys] = stat1[keys]
+ return newstat
+
+def aggregate(stat1, stat2):