--- /dev/null
+// 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 xcontext is a package to offer the extra functionality we need
+// from contexts that is not available from the standard context package.
+package xcontext
+
+import (
+ "context"
+ "time"
+)
+
+// Detach returns a context that keeps all the values of its parent context
+// but detaches from the cancellation and error handling.
+func Detach(ctx context.Context) context.Context { return detachedContext{ctx} }
+
+type detachedContext struct{ parent context.Context }
+
+func (v detachedContext) Deadline() (time.Time, bool) { return time.Time{}, false }
+func (v detachedContext) Done() <-chan struct{} { return nil }
+func (v detachedContext) Err() error { return nil }
+func (v detachedContext) Value(key interface{}) interface{} { return v.parent.Value(key) }