Package netns allows ultra-simple network namespace handling. NsHandles can be retrieved and set. Note that the current namespace is thread local so actions that set and reset namespaces should use LockOSThread to make sure the namespace doesn't change due to a goroutine switch. It is best to close NsHandles when you are done with them. This can be accomplished via a `defer ns.Close()` on the handle. Changing namespaces requires elevated privileges, so in most cases this code needs to be run as root.