docs: function(arr, num, padding) {
      var pad = isDefined(padding);
      var result = new Array(num);
      var divisor = ceil(arr.length / num);
      simpleRepeat(num, function(i) {
        var index = i * divisor;
        var group = arr.slice(index, index + divisor);
        if (pad && group.length < divisor) {
          simpleRepeat(divisor - group.length, function() {
            group.push(padding);
          });
        }
        result[i] = group;
      });
      return result;
    }