group spans by resources and create batches for each.

[jkwatson]

The span part of implementing #67

[breedx-nr]

This is interesting. I don't have any real feedback on the code itself (looks good to me) but I do wonder about Resource being used as a map key while being abstract and not having explicit equals+hashode.

I also think that if you are interested at this level of performance tuning for the wire, it might also be good to take a look at newrelic/newrelic-telemetry-sdk-java#5 to potentially save round trips.

[jkwatson]

Resource is abstract because it uses AutoValue to generate the implementation. This means it has a stable equals/hashcode by design.

[jkwatson]

And, yes, we if we implement newrelic/newrelic-telemetry-sdk-java#5 , we can definitely reduce round-trips, as well.

[breedx-nr]

Oh yes autovalue. :). Well, I think we should try this out...thanks!