func Unregister(t TracerSig) {
	c := t.Sigchan()
	if c == nil {
		return
	}

	unregisterInternal(t, c)
}
func Unregister(t TracerSig) {
	c := t.Sigchan()
	if c == nil {
		return
	}

	unregisterInternal(t, c)
}
// Stops the specified TracerSig from handling any signals it was previously
// registered to handle via bcd.Register().