| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/docker/distribution/reference | Package reference is deprecated, and has moved to github.com/distribution/reference. |
| github.com/docker/docker/pkg/stringid | Package stringid provides helper functions for dealing with string identifiers |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |