| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| errors | Package errors implements functions to manipulate errors. |
| 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. |
| github.com/golang/protobuf/ptypes | Package ptypes provides functionality for interacting with well-known types. |
| google.golang.org/genproto/googleapis/rpc/status | |
| google.golang.org/grpc/codes | Package codes defines the canonical error codes used by gRPC. |
| google.golang.org/grpc/internal | Package internal contains gRPC-internal code, to avoid polluting the godoc of the top-level grpc package. |