diff --git a/vendor/google.golang.org/protobuf/proto/checkinit.go b/vendor/google.golang.org/protobuf/proto/checkinit.go
new file mode 100644
index 0000000..3e9a6a2
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/proto/checkinit.go
@@ -0,0 +1,71 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"google.golang.org/protobuf/internal/errors"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/runtime/protoiface"
+)
+
+// CheckInitialized returns an error if any required fields in m are not set.
+func CheckInitialized(m Message) error {
+	// Treat a nil message interface as an "untyped" empty message,
+	// which we assume to have no required fields.
+	if m == nil {
+		return nil
+	}
+
+	return checkInitialized(m.ProtoReflect())
+}
+
+// CheckInitialized returns an error if any required fields in m are not set.
+func checkInitialized(m protoreflect.Message) error {
+	if methods := protoMethods(m); methods != nil && methods.CheckInitialized != nil {
+		_, err := methods.CheckInitialized(protoiface.CheckInitializedInput{
+			Message: m,
+		})
+		return err
+	}
+	return checkInitializedSlow(m)
+}
+
+func checkInitializedSlow(m protoreflect.Message) error {
+	md := m.Descriptor()
+	fds := md.Fields()
+	for i, nums := 0, md.RequiredNumbers(); i < nums.Len(); i++ {
+		fd := fds.ByNumber(nums.Get(i))
+		if !m.Has(fd) {
+			return errors.RequiredNotSet(string(fd.FullName()))
+		}
+	}
+	var err error
+	m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+		switch {
+		case fd.IsList():
+			if fd.Message() == nil {
+				return true
+			}
+			for i, list := 0, v.List(); i < list.Len() && err == nil; i++ {
+				err = checkInitialized(list.Get(i).Message())
+			}
+		case fd.IsMap():
+			if fd.MapValue().Message() == nil {
+				return true
+			}
+			v.Map().Range(func(key protoreflect.MapKey, v protoreflect.Value) bool {
+				err = checkInitialized(v.Message())
+				return err == nil
+			})
+		default:
+			if fd.Message() == nil {
+				return true
+			}
+			err = checkInitialized(v.Message())
+		}
+		return err == nil
+	})
+	return err
+}