func trimPrefix(p, prefix string) (s string) {
	s = strings.TrimPrefix(p, prefix)
	s = strings.TrimPrefix(s, "/")
	return
}
func trimPrefix(p, prefix string) (s string) {
	s = strings.TrimPrefix(p, prefix)
	s = strings.TrimPrefix(s, "/")
	return
}
// trimPrefix removes a given prefix and any slash following the prefix
// e.g.: trimPrefix("foo", "foo") == trimPrefix("foo/", "foo") == ""