Imports go.opentelemetry.io/otel/api/metric go.opentelemetry.io/otel/exporters/metric/prometheus go.opentelemetry.io/otel/label go.opentelemetry.io/otel/sdk/metric/controller/pull go.opentelemetry.io/otel/sdk/resource Standard library imports net/http/httptest bytes context fmt io/ioutil log net/http