code: private void removeFromInternalState(Component panel) {
  		this.fullTabList.remove(panel);
  		if (this.hiddenTabs.remove(panel)) {
  			handleHiddenTabListTab();
  		}
  	}
docs: Removes the given panel/component from the internal state, that is, from {@link #fullTabList} and {@link #hiddenTabs}.
  
  @param panel the panel/component to remove.