Code example for DataSetObservable

Methods: unregisterObserver

	public void registerDataSetObserver(DataSetObserver observer) {
	public void unregisterDataSetObserver(DataSetObserver observer) {
	 * This method may be called by the ViewPager to obtain a title string 
	 * to describe the specified page. This method may return null 
	 * indicating no title for this page. The default implementation returns 
	 * null. 
	 * @param position The position of the title requested 
	 * @return A title for the requested page 
	public CharSequence getPageTitle(int position) {
		return null;