code: function createDropdownMenu(dropdown) {
      var $menu = $('<div>', {
          'class': 'dropdown-menu',
          'html': '<div class="dropdown-caret"><span class="caret-outer"></span><span class="caret-inner"></span></div>'
      });
  
      if (_.isString(dropdown)) {
          $menu.append(dropdown);
      } else {
          var groups = _.map(dropdown, function(group) {
              if (_.isArray(group)) return group;
              else return [group];
          });
  
          // Create buttons groups
          _.each(groups, function(group) {
              var $group = $('<div>', {
                  'class': 'buttons'
              });
              var sizeClass = 'size-'+group.length;
  
              // Append buttons
              _.each(group, function(btn) {
                  btn = _.defaults(btn || {}, {
                      text: '',
                      className: '',
                      onClick: defaultOnClick
                  });
  
                  var $btn = $('<button>', {
                      'class': 'button '+sizeClass+' '+btn.className,
                      'text': btn.text
                  });
                  $btn.click(btn.onClick);
  
                  $group.append($btn);
              });
  
  
              $menu.append($group);
          });
  
      }
  
  
      return $menu;
  }
docs: Create a dropdown menu