if ContainsRune(ct.b, ct.r) != ct.expected {
			t.Errorf("ContainsRune(%q, %q) = %v, want %v",
				ct.b, ct.r, !ct.expected, ct.expected)
		}
	}
}

func TestContainsFunc(t *testing.T) {
	for _, ct := range ContainsRuneTests {
		if ContainsFunc(ct.b, func(r rune) bool {
			return ct.r == r
		}) != ct.expected {
			t.Errorf("ContainsFunc(%q, func(%q)) = %v, want %v",