code: function (data) {
              var ids = [], filtered = [], self = this;
  
              // filter out duplicates
              $(data).each(function () {
                  if (indexOf(self.id(this), ids) < 0) {
                      ids.push(self.id(this));
                      filtered.push(this);
                  }
              });
              data = filtered;
  
              this.selection.find(".select2-search-choice").remove();
              $(data).each(function () {
                  self.addSelectedChoice(this);
              });
              self.postprocessResults();
          }
docs: multi