type predicate struct {
	f    func(r rune) bool
	name string
}

var isSpace = predicate{unicode.IsSpace, "IsSpace"}
var isDigit = predicate{unicode.IsDigit, "IsDigit"}
var isUpper = predicate{unicode.IsUpper, "IsUpper"}
var isValidRune = predicate{
	func(r rune) bool {
		return r != utf8.RuneError
	},
	"IsValidRune",
}

type TrimFuncTest struct {
	f        predicate