github.com/golang/protobuf/jsonpb.anyResolver.FindExtensionByName (method, view implemented interface methods)

one use

	github.com/golang/protobuf/jsonpb (current package)
		json.go#L43: func (r anyResolver) FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) {