[metric spec review] API not mentioned in the spec but provided by the implementation

[dyladan]

    API not mentioned in the spec but provided by the implementation:

• opentelemetry-js/api/src/metrics/Meter.ts

  Line 142 in d154066

  addBatchObservableCallback<AttributesTypes extends MetricAttributes = MetricAttributes>(

• opentelemetry-js/api/src/metrics/Meter.ts

  Line 156 in d154066

  removeBatchObservableCallback<AttributesTypes extends MetricAttributes = MetricAttributes>(

Originally posted by @reyang in open-telemetry/community#1204 (comment)

[dyladan]

API not mentioned in the spec but provided by the implementation:

• opentelemetry-js/api/src/metrics/Meter.ts

  Line 142 in d154066

  addBatchObservableCallback<AttributesTypes extends MetricAttributes = MetricAttributes>(

• opentelemetry-js/api/src/metrics/Meter.ts

  Line 156 in d154066

  removeBatchObservableCallback<AttributesTypes extends MetricAttributes = MetricAttributes>(

This is defined in the spec, with an implementation specialized name: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#multiple-instrument-callbacks. Also, the spec requires the registered callbacks to be able to be unregistered: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#asynchronous-counter-operations.

originally posted by @legendecas

[pichlermarc]

I think @legendecas' answer addresses the concerns sufficiently. WDYT @open-telemetry/javascript-maintainers? 🤔