Returning to isJq:
1. Method name means what it do, not what it expect as argument or which object it contains.
2. What i really means:
```js
function isJq(predicate) {
Assertion.add(predicate, function() {
     this.params = { operator: 'to be ' + predicate };
     this.assert($(this.obj).is(':'+predicate));
  }, true);
}
```
and call it 6 times (maybe i miss something), makes sense?