Did you tried the test that?^^;
Difficult to explain in English so I attach the source code.

in /app/ios.js
```javascript
...
  , deviceCommon = require('./device')
...
IOS.prototype.lookForAlert = function(cb, counter, looks, timeout) {
  var me = this;
  .....
  ....
      me.proxy("au.alertIsPresent()", function(err, res) {
        .....
        ....
      }
};
....
IOS.prototype.proxy = deviceCommon.proxy;
....
```
so I think command might be an array