* New label set API
* Checkpoint
* Remove label.Labels interface
* Fix trace
* Remove label storage
* Restore metric_test.go
* Tidy tests
* More comments
* More comments
* Same changes as 654
* Checkpoint
* Fix batch labels
* Avoid Resource.Attributes() where possible
* Update comments and restore order in resource.go
* From feedback
* From feedback
* Move iterator_test & feedback
* Strenghten the label.Set test
* Feedback on typos
* Fix the set test per @krnowak
* Nit
* Add check to sum transform for unknown NumberKind
* Initial batching
* Move CheckpointSet transform to internal package
* Add tests for the Exporter Export method
Check batching and general output exporter ResourceMetrics are correct.
* Check errors in tests
* Apply suggestions from code review
Co-Authored-By: Krzesimir Nowak <qdlacz@gmail.com>
* Use var instead of multiple calls for group IDs
* Fix otlp metric test reporting
Co-authored-by: Krzesimir Nowak <qdlacz@gmail.com>