function testAllSuffixesWithValues(attrName, allowedValues) {
      var breakpoints = [''].concat(suffixes);

      angular.forEach(breakpoints, function(suffix) {
        angular.forEach(allowedValues, function(value) {
          var className = suffix ? attrName + "-" + suffix : attrName;
          testWithValue(className, value, attrName);
        });
      });
    }
For the specified attrName (e.g. flex) test all breakpoints
with all allowed values.