daemon/daemon_overlay.go - third_party/github.com/moby/moby - Git at Google

 // +build !exclude_graphdriver_overlay,linux

 package daemon

 import (
 	_ "github.com/docker/docker/daemon/graphdriver/overlay"
 )
	// +build !exclude_graphdriver_overlay,linux

	package daemon

	import (
	_ "github.com/docker/docker/daemon/graphdriver/overlay"
	)