Imports github.com/golang/protobuf/proto github.com/golang/protobuf/ptypes github.com/envoyproxy/protoc-gen-validate/validate github.com/cncf/udpa/go/udpa/annotations github.com/golang/protobuf/ptypes/wrappers github.com/golang/protobuf/ptypes/duration Standard library imports bytes errors fmt math net net/url regexp strings time unicode/utf8 net/mail