| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| flag | Package flag implements command-line flag parsing. |
| github.com/docker/docker/testutil | Package testutil contains common testing tasks like running dockerd. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| runtime/debug | Package debug contains facilities for programs to debug themselves while they are running. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| testing | Package testing provides support for automated testing of Go packages. |