| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| go.opencensus.io/metric/metricdata | Package metricdata contains the metrics data model. |
| go.opencensus.io/stats/internal | |
| go.opencensus.io/tag | Package tag contains OpenCensus tags. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |