diff --git a/vendor/google.golang.org/protobuf/proto/equal.go b/vendor/google.golang.org/protobuf/proto/equal.go
new file mode 100644
index 0000000..4dba2b9
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/proto/equal.go
@@ -0,0 +1,167 @@
+// 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 (
+	"bytes"
+	"math"
+	"reflect"
+
+	"google.golang.org/protobuf/encoding/protowire"
+	pref "google.golang.org/protobuf/reflect/protoreflect"
+)
+
+// Equal reports whether two messages are equal.
+// If two messages marshal to the same bytes under deterministic serialization,
+// then Equal is guaranteed to report true.
+//
+// Two messages are equal if they belong to the same message descriptor,
+// have the same set of populated known and extension field values,
+// and the same set of unknown fields values. If either of the top-level
+// messages are invalid, then Equal reports true only if both are invalid.
+//
+// Scalar values are compared with the equivalent of the == operator in Go,
+// except bytes values which are compared using bytes.Equal and
+// floating point values which specially treat NaNs as equal.
+// Message values are compared by recursively calling Equal.
+// Lists are equal if each element value is also equal.
+// Maps are equal if they have the same set of keys, where the pair of values
+// for each key is also equal.
+func Equal(x, y Message) bool {
+	if x == nil || y == nil {
+		return x == nil && y == nil
+	}
+	mx := x.ProtoReflect()
+	my := y.ProtoReflect()
+	if mx.IsValid() != my.IsValid() {
+		return false
+	}
+	return equalMessage(mx, my)
+}
+
+// equalMessage compares two messages.
+func equalMessage(mx, my pref.Message) bool {
+	if mx.Descriptor() != my.Descriptor() {
+		return false
+	}
+
+	nx := 0
+	equal := true
+	mx.Range(func(fd pref.FieldDescriptor, vx pref.Value) bool {
+		nx++
+		vy := my.Get(fd)
+		equal = my.Has(fd) && equalField(fd, vx, vy)
+		return equal
+	})
+	if !equal {
+		return false
+	}
+	ny := 0
+	my.Range(func(fd pref.FieldDescriptor, vx pref.Value) bool {
+		ny++
+		return true
+	})
+	if nx != ny {
+		return false
+	}
+
+	return equalUnknown(mx.GetUnknown(), my.GetUnknown())
+}
+
+// equalField compares two fields.
+func equalField(fd pref.FieldDescriptor, x, y pref.Value) bool {
+	switch {
+	case fd.IsList():
+		return equalList(fd, x.List(), y.List())
+	case fd.IsMap():
+		return equalMap(fd, x.Map(), y.Map())
+	default:
+		return equalValue(fd, x, y)
+	}
+}
+
+// equalMap compares two maps.
+func equalMap(fd pref.FieldDescriptor, x, y pref.Map) bool {
+	if x.Len() != y.Len() {
+		return false
+	}
+	equal := true
+	x.Range(func(k pref.MapKey, vx pref.Value) bool {
+		vy := y.Get(k)
+		equal = y.Has(k) && equalValue(fd.MapValue(), vx, vy)
+		return equal
+	})
+	return equal
+}
+
+// equalList compares two lists.
+func equalList(fd pref.FieldDescriptor, x, y pref.List) bool {
+	if x.Len() != y.Len() {
+		return false
+	}
+	for i := x.Len() - 1; i >= 0; i-- {
+		if !equalValue(fd, x.Get(i), y.Get(i)) {
+			return false
+		}
+	}
+	return true
+}
+
+// equalValue compares two singular values.
+func equalValue(fd pref.FieldDescriptor, x, y pref.Value) bool {
+	switch fd.Kind() {
+	case pref.BoolKind:
+		return x.Bool() == y.Bool()
+	case pref.EnumKind:
+		return x.Enum() == y.Enum()
+	case pref.Int32Kind, pref.Sint32Kind,
+		pref.Int64Kind, pref.Sint64Kind,
+		pref.Sfixed32Kind, pref.Sfixed64Kind:
+		return x.Int() == y.Int()
+	case pref.Uint32Kind, pref.Uint64Kind,
+		pref.Fixed32Kind, pref.Fixed64Kind:
+		return x.Uint() == y.Uint()
+	case pref.FloatKind, pref.DoubleKind:
+		fx := x.Float()
+		fy := y.Float()
+		if math.IsNaN(fx) || math.IsNaN(fy) {
+			return math.IsNaN(fx) && math.IsNaN(fy)
+		}
+		return fx == fy
+	case pref.StringKind:
+		return x.String() == y.String()
+	case pref.BytesKind:
+		return bytes.Equal(x.Bytes(), y.Bytes())
+	case pref.MessageKind, pref.GroupKind:
+		return equalMessage(x.Message(), y.Message())
+	default:
+		return x.Interface() == y.Interface()
+	}
+}
+
+// equalUnknown compares unknown fields by direct comparison on the raw bytes
+// of each individual field number.
+func equalUnknown(x, y pref.RawFields) bool {
+	if len(x) != len(y) {
+		return false
+	}
+	if bytes.Equal([]byte(x), []byte(y)) {
+		return true
+	}
+
+	mx := make(map[pref.FieldNumber]pref.RawFields)
+	my := make(map[pref.FieldNumber]pref.RawFields)
+	for len(x) > 0 {
+		fnum, _, n := protowire.ConsumeField(x)
+		mx[fnum] = append(mx[fnum], x[:n]...)
+		x = x[n:]
+	}
+	for len(y) > 0 {
+		fnum, _, n := protowire.ConsumeField(y)
+		my[fnum] = append(my[fnum], y[:n]...)
+		y = y[n:]
+	}
+	return reflect.DeepEqual(mx, my)
+}