diff --git a/unum/vendor/golang.org/x/net/internal/nettest/helper_stub.go b/unum/vendor/golang.org/x/net/internal/nettest/helper_stub.go
new file mode 100644
index 0000000..ea61b6f
--- /dev/null
+++ b/unum/vendor/golang.org/x/net/internal/nettest/helper_stub.go
@@ -0,0 +1,32 @@
+// Copyright 2014 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.
+
+// +build nacl plan9
+
+package nettest
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func maxOpenFiles() int {
+	return defaultMaxOpenFiles
+}
+
+func supportsRawIPSocket() (string, bool) {
+	return fmt.Sprintf("not supported on %s", runtime.GOOS), false
+}
+
+func supportsIPv6MulticastDeliveryOnLoopback() bool {
+	return false
+}
+
+func causesIPv6Crash() bool {
+	return false
+}
+
+func protocolNotSupported(err error) bool {
+	return false
+}