code: private void expand(boolean immediately) {
  	if (locked == false && inAction == false && collapsed) {
  	  inAction = true;
  	  CollapsiblePanelListener[] array =
  		  listeners.getListeners(CollapsiblePanelListener.class);
  	  for (CollapsiblePanelListener cpl : array) {
  		cpl.panelWillExpand(new CollapsiblePanelEvent(this));
  	  }
  	  pixels = incremental;
  	  if (isAnimationEnabled() && immediately == false) {
  		calculatedHeight = getSize().height;
  		if (isFillMode()) {
  		  setEndHeights();
  		} else {
  		  endHeight = getPreferredSize(false).height;
  		}
  		getExpandTimer().start();
  	  } else {
  		changeStatus();
  	  }
  	}
    }
docs: Expand the panel.
  
  @param immediately
  a boolean value, where true expand immediately the panel and false
  not.