}
		for _, c := range s {
			if !strings.ContainsRune(valid, c) {
				t.Errorf("expected valid characters, got %v", c)
			}
		}
	}
}

// Confirm that panic occurs on invalid input.
func TestRangePanic(t *testing.T) {
	defer func() {
		if err := recover(); err == nil {
			t.Errorf("Panic didn't occur!")
		}
	}()
	// Should result in an error...
	Intn(0)
}

func TestIntn(t *testing.T) {