Bug 89917 [formatter] UI for "Keep empty array initializer on one line" option is confusing
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/formatter/ModifyDialogTabPage.java
/**
	 * This is the default listener for any of the Preference
	 * classes. It is added by the respective factory methods and
	 * updates the page's preview on each change. 
	 */
	protected final Observer fUpdater= new Observer() {
		public void update(Observable o, Object arg) {
			doUpdatePreview();
			notifyValuesModified();
		}
	};
	
	
	/**
	 * The base class of all Preference classes. A preference class provides a wrapper
	 * around one or more SWT widgets and handles the input of values for some key.
	 * On each change, the new value is written to the map and the listeners are notified.
	 */
	protected abstract class Preference extends Observable {