r := NewReader(strings.NewReader("x"))
	r.ReadRune()
	r.Peek(1)
	r.UnreadRune()
	r.ReadRune() // Used to panic here
}

var testOutput = []byte("0123456789abcdefghijklmnopqrstuvwxy")
var testInput = []byte("012\n345\n678\n9ab\ncde\nfgh\nijk\nlmn\nopq\nrst\nuvw\nxy")
var testInputrn = []byte("012\r\n345\r\n678\r\n9ab\r\ncde\r\nfgh\r\nijk\r\nlmn\r\nopq\r\nrst\r\nuvw\r\nxy\r\n\n\r\n")

	{"abc", "c", "ab", "", true},
	{"abc", "abc", "", "", true},
	{"abc", "", "", "abc", true},
	{"abc", "d", "abc", "", false},
	{"", "d", "", "", false},
	{"", "", "", "", true},
}

func TestCut(t *testing.T) {
	for _, tt := range cutTests {
		if before, after, found := Cut([]byte(tt.s), []byte(tt.sep)); string(before) != tt.before || string(after) != tt.after || found != tt.found {