func (p *Pinger) Stop() {
	p.debugln("Stop(): close(p.ctx.stop)")
	close(p.ctx.stop)
	p.debugln("Stop(): <-p.ctx.done")
	<-p.ctx.done
}
func (p *Pinger) Stop() {
	p.debugln("Stop(): close(p.ctx.stop)")
	close(p.ctx.stop)
	p.debugln("Stop(): <-p.ctx.done")
	<-p.ctx.done
}
func ( p * Pinger ) Stop ( ) { p . debugln ( " " ) close ( p . ctx . stop ) p . debugln ( " " ) <- p . ctx . done }
// Stop stops RunLoop(). It must be called after RunLoop(). If not, it causes
// panic.
Stop stops RunLoop () . It must be called after RunLoop () . If not it causes panic .