void registerEditableSdk(@NotNull Sdk editable) {
      // called from any thread
      //
      // there are many Sdk clones that are created
      // along with the Project Structure model.
      // Our goal is to keep track of all such objects to make
      // sure we update all and refresh the UI once download is completed
      //
      // there is a chance we have here several unneeded objects,
      // e.g. from the Project Structure dialog is shown several
      // times. It's cheaper to ignore then to track
      myEditableSdks.add(editable);
    }
void registerEditableSdk(@NotNull Sdk editable)