code: function(options, select) {
                  if (options.length === 0) {
                      return this.nonSelectedText;
                  }
                  else if (this.allSelectedText
                           && options.length === $('option', $(select)).length
                           && $('option', $(select)).length !== 1
                           && this.multiple) {
  
                      if (this.selectAllNumber) {
                          return this.allSelectedText + ' (' + options.length + ')';
                      }
                      else {
                          return this.allSelectedText;
                      }
                  }
                  else if (options.length > this.numberDisplayed) {
                      return options.length + ' ' + this.nSelectedText;
                  }
                  else {
                      var selected = '';
                      var delimiter = this.delimiterText;
  
                      options.each(function() {
                          var label = ($(this).attr('label') !== undefined) ? $(this).attr('label') : $(this).text();
                          selected += label + delimiter;
                      });
  
                      return selected.substr(0, selected.length - 2);
                  }
              }
docs: Default text function will either print 'None selected' in case no
  option is selected or a list of the selected options up to a length
  of 3 selected options.
  
  @param {jQuery} options
  @param {jQuery} select
  @returns {String}