Imports of package metric

PathSynopsis
contextPackage context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes.
go.opentelemetry.io/otel/api/label
go.opentelemetry.io/otel/api/metric
go.opentelemetry.io/otel/sdk/resourcePackage resource provides detecting and representing resources.
syncPackage sync provides basic synchronization primitives such as mutual exclusion locks.