| flag | Package flag implements command-line flag parsing. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/lightstep/lightstep-tracer-go | Package lightstep implements the LightStep OpenTracing client for Go. |
| github.com/opentracing/opentracing-go | |
| github.com/opentracing/opentracing-go/log | |
| golang.org/x/net/context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| time | Package time provides functionality for measuring and displaying time. |