code: function(values, triggerChange) {
              var self=this, ids, old;
              if (arguments.length === 0) {
                   return this.selection
                       .children(".select2-search-choice")
                       .map(function() { return $(this).data("select2-data"); })
                       .get();
              } else {
                  old = this.data();
                  if (!values) { values = []; }
                  ids = $.map(values, function(e) { return self.opts.id(e); });
                  this.setVal(ids);
                  this.updateSelection(values);
                  this.clearSearch();
                  if (triggerChange) {
                      this.triggerChange(this.buildChangeDetails(old, this.data()));
                  }
              }
          }
docs: multi