| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/golang/protobuf/proto | Package proto provides functionality for handling protocol buffer messages. |
| 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. |
| google.golang.org/appengine/internal | Package internal provides support for package appengine. |
| net/http | Package http provides HTTP client and server implementations. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| testing | Package testing provides support for automated testing of Go packages. |