Validation problem

I'm trying todo

```javascript
var StringMask = require("string-mask")

var formatter = new StringMask('UUAA AAAA AAAA AAAA AAAA AAAA AAA');
var result = formatter.apply('FR761111900069410000AA33222');

console.log(formatter.validate(result)) //it prints false 
```

Shouldn't it print `true`?