Add unit tests

vendor/google.golang.org/protobuf/internal/genid/map_entry.go

@@ -0,0 +1,16 @@
+// 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 genid
+
+import protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+
+// Generic field names and numbers for synthetic map entry messages.
+const (
+	MapEntry_Key_field_name   protoreflect.Name = "key"
+	MapEntry_Value_field_name protoreflect.Name = "value"
+
+	MapEntry_Key_field_number   protoreflect.FieldNumber = 1
+	MapEntry_Value_field_number protoreflect.FieldNumber = 2
+)