Bug 142432 MasterPage from library can't be restored to modify
Details: MasterPage from library can't be restored to modify Step: 1.New a library named lib1, and insert a masterpage named lib-mp. 2.Publish the library into resource folder. 3.New a report design and use lib1. 4.Drop the lib-mp from library explorer into outline of report design. 5.Double click lib-mp, and switch to Property editro tab. 6.Click restore. Actual result: Pop up an error message and said that the master page cannot specify size the page type is not custom.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
* @param obj
	 *            the listener to de-register
	 */
	public void removeListener( Listener obj )
	{
		getElement( ).removeListener( obj );
	}
	/**
	 * Returns an iterator over the elements that derive from this one.
	 * 
	 * @return an iterator over the elements that derive from this one. Each
	 *         item returned by the iterator's <code>getNext( )</code> method
	 *         is of type {@link DesignElementHandle}.
	 */
	public Iterator derivedIterator( )
	{
		return new DerivedElementIterator( module, this );
	}
	/**
	 * Returns an iterator over the clients of this element. Useful only for
	 * styles. Returns a list of all the elements that use this style.
	 * 
	 * @return an iterator over the clients of this element. Each item returned
	 *         by the iterator's <code>getNext( )</code> method is of type
	 *         {@link DesignElementHandle}. Nothing will be iterated over an
	 *         element that is not <code>ReferenceableElement</code>.
	 */
	public Iterator clientsIterator( )
	{
		return new ClientIterator( this );