Working with Well-Known Types

import "google/protobuf/timestamp.proto";
message Event {
  string id = 1;
  google.protobuf.Timestamp occurred_at = 2;
}

import "google.golang.org/protobuf/types/known/anypb"

a, _ := anypb.New(&User{Id: "u1"})
var u User
_ = a.UnmarshalTo(&u)

import "google/protobuf/empty.proto";
service Health {
  rpc Ping(google.protobuf.Empty) returns (google.protobuf.Empty);
}

import "google/protobuf/field_mask.proto";
message UpdateUserRequest {
  User user = 1;
  google.protobuf.FieldMask update_mask = 2;   // e.g. paths="email,profile.name"
}