How to collect data from conditional edges?

[luoling1993]

In StateGraph, the state is a dictionary that records the time spent or token usage of a node. Node will return the state content, which can be easily maintained, but the condition edge will not return the state, resulting in the condition edge time-consuming or token usage can not return the result. Although it is possible to implement a TimeCost or TokenUsage class as a global variable to record time or token usage at each node or condition edge, this is not very elegant after all, there is no framework level to implement this requirement.