code: function parameterize(values, notSetValue) {
      if (typeof values === 'function') {
        return this.parameter(values);
      }
      values = Array.isArray(values) ? values : [values];
      var str = '',
          i = -1;
      while (++i < values.length) {
        if (i > 0) {
          str += ', ';
        }
        str += this.parameter(values[i] === undefined ? notSetValue : values[i]);
      }
      return str;
    }
docs: Turns a list of values into a list of ?'s, joining them with commas unless a "joining" value is specified (e.g. ' and ')