How come n_bytes and n_packets fields are not included in the Flow structure?

I am using this library to parse OVS flows, and I need the `n_bytes` and `n_packets` information of the flow. I noticed that these fields are ignored in the `UnmarshalText` function. I think it would be beneficial if I could access `n_bytes` and `n_packets` directly from the `Flow` structure.

I solved my problem by using the `DumpAggregate` function. However, in my case, I need to retrieve the `n_bytes` of many flows, which results in numerous `DumpAggregate` calls instead of a single `DumpFlows` call.

I'm curious whether this behavior is intentional or simply not yet implemented. If there are no other considerations, I would be willing to contribute some code to address this issue.