Removed hardcoded class names from $.fn.select2. The code now uses the exports accessible through window.Select2 to instantiate widgets, allowing the environment to replace or extend those classes globally.

select2.js

@@ -3185,7 +3185,7 @@ the specific language governing permissions and limitations under the Apache Lic
                     if ("tags" in opts) {opts.multiple = multiple = true;}
                 }
 
-                select2 = multiple ? new MultiSelect2() : new SingleSelect2();
+                select2 = multiple ? new window.Select2["class"].multi() : window.Select2["class"].single();
                 select2.init(opts);
             } else if (typeof(args[0]) === "string") {