code: private Stage getStage(final StageWaveBean swb, final Scene scene) {
  
          Stage stage = swb.stage();
          if (stage == null) {
              stage = new Stage();
          }
          stage.setScene(scene);
  
          return stage;
      }
docs: Gets the stage.
  
  @param swb the waveBean holding default values
  @param scene the scene
  
  @return the stage