| 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/ptypes/duration | |
| github.com/golang/protobuf/ptypes/timestamp | |
| google.golang.org/grpc | Package grpc implements an RPC system called gRPC. |
| google.golang.org/grpc/balancer | Package balancer defines APIs for load balancing in gRPC. |
| google.golang.org/grpc/balancer/grpclb/grpc_lb_v1 | |
| google.golang.org/grpc/codes | Package codes defines the canonical error codes used by gRPC. |
| google.golang.org/grpc/connectivity | Package connectivity defines connectivity semantics. |
| google.golang.org/grpc/credentials | Package credentials implements various credentials supported by gRPC library, which encapsulate all the state needed by a client to authenticate with a server and make various assertions, e.g., about the client's identity, role, or whether it is authorized to make a particular call. |
| google.golang.org/grpc/grpclog | Package grpclog defines logging for grpc. |
| google.golang.org/grpc/internal | Package internal contains gRPC-internal code, to avoid polluting the godoc of the top-level grpc package. |
| google.golang.org/grpc/internal/backoff | Package backoff implement the backoff strategy for gRPC. |
| google.golang.org/grpc/internal/channelz | Package channelz defines internal APIs for enabling channelz service, entry registration/deletion, and accessing channelz data. |
| google.golang.org/grpc/metadata | Package metadata define the structure of the metadata supported by gRPC library. |
| google.golang.org/grpc/resolver | Package resolver defines APIs for name resolution in gRPC. |
| google.golang.org/grpc/status | Package status implements errors returned by gRPC. |
| io | Package io provides basic interfaces to I/O primitives. |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |
| time | Package time provides functionality for measuring and displaying time. |