| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| google.golang.org/protobuf/internal/encoding/messageset | Package messageset encodes and decodes the obsolete MessageSet wire format. |
| google.golang.org/protobuf/internal/errors | Package errors implements functions to manipulate errors. |
| google.golang.org/protobuf/internal/flags | Package flags provides a set of flags controlled by build tags. |
| google.golang.org/protobuf/reflect/protoreflect | Package protoreflect provides interfaces to dynamically manipulate messages. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |