diff --git a/vendor/google.golang.org/protobuf/proto/size_gen.go b/vendor/google.golang.org/protobuf/proto/size_gen.go
new file mode 100644
index 0000000..1118460
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/proto/size_gen.go
@@ -0,0 +1,55 @@
+// Copyright 2018 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.
+
+// Code generated by generate-types. DO NOT EDIT.
+
+package proto
+
+import (
+	"google.golang.org/protobuf/encoding/protowire"
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+func sizeSingular(num protowire.Number, kind protoreflect.Kind, v protoreflect.Value) int {
+	switch kind {
+	case protoreflect.BoolKind:
+		return protowire.SizeVarint(protowire.EncodeBool(v.Bool()))
+	case protoreflect.EnumKind:
+		return protowire.SizeVarint(uint64(v.Enum()))
+	case protoreflect.Int32Kind:
+		return protowire.SizeVarint(uint64(int32(v.Int())))
+	case protoreflect.Sint32Kind:
+		return protowire.SizeVarint(protowire.EncodeZigZag(int64(int32(v.Int()))))
+	case protoreflect.Uint32Kind:
+		return protowire.SizeVarint(uint64(uint32(v.Uint())))
+	case protoreflect.Int64Kind:
+		return protowire.SizeVarint(uint64(v.Int()))
+	case protoreflect.Sint64Kind:
+		return protowire.SizeVarint(protowire.EncodeZigZag(v.Int()))
+	case protoreflect.Uint64Kind:
+		return protowire.SizeVarint(v.Uint())
+	case protoreflect.Sfixed32Kind:
+		return protowire.SizeFixed32()
+	case protoreflect.Fixed32Kind:
+		return protowire.SizeFixed32()
+	case protoreflect.FloatKind:
+		return protowire.SizeFixed32()
+	case protoreflect.Sfixed64Kind:
+		return protowire.SizeFixed64()
+	case protoreflect.Fixed64Kind:
+		return protowire.SizeFixed64()
+	case protoreflect.DoubleKind:
+		return protowire.SizeFixed64()
+	case protoreflect.StringKind:
+		return protowire.SizeBytes(len(v.String()))
+	case protoreflect.BytesKind:
+		return protowire.SizeBytes(len(v.Bytes()))
+	case protoreflect.MessageKind:
+		return protowire.SizeBytes(sizeMessage(v.Message()))
+	case protoreflect.GroupKind:
+		return protowire.SizeGroup(num, sizeMessage(v.Message()))
+	default:
+		return 0
+	}
+}