private void Unplug(PIF p)
        {
            if (!p.currently_attached)
            {
                // We will try and unplug the PIF even if it seems to be already unplugged (CA-75969)
                log.DebugFormat("Unplugging PIF '{0}': this PIF is not currently attached. Will try to unplug anyway", p.uuid);
            }

            PIF.unplug(Session, p.opaque_ref);
        }