| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/opentracing-contrib/go-stdlib/nethttp | |
| github.com/opentracing/opentracing-go | |
| github.com/opentracing/opentracing-go/ext | |
| github.com/opentracing/opentracing-go/log | |
| io | Package io provides basic interfaces to I/O primitives. |
| net/http | Package http provides HTTP client and server implementations. |