| 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/golang/protobuf/internal/gengogrpc | Package gengogrpc contains the gRPC code generator. |
| google.golang.org/protobuf/cmd/protoc-gen-go/internal_gengo | Package internal_gengo is internal to the protobuf module. |
| google.golang.org/protobuf/compiler/protogen | Package protogen provides support for writing protoc plugins. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |