code: function() {
          var input = this.element,
              wrapper = this.render(this.options.template)
                  .insertBefore(input)
                  .append(input);
  
          if (this.options.copyClasses) {
              this.copyClasses(input, wrapper);
          }
  
          return wrapper;
      }
docs: Build the element to wrap custom inputs with.
  Copy over the original class names.
  
  @returns {jQuery}