Apart from this, another thing to keep in mind that the correct usage of the localization capability regarding the 'callDurationMinutes' property would be something such as:
´´´javascript
_('callDurationMinutes', {mm: '12', ss: '34'}); // In English this would return '12:34'.
````
But keep in mind that we are not dealing with the real L10n libraries but with the mock ones and the previous code will return the key and not magically generate a string containing numbers.