Bug 214706 Script UID doens't work for Chart
Use chart "onRender" property handle and call ModuleUtil.getScriptUID(), it generates the id. But later use this id to get back the PropertyHandle or Script content, it fails.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/PropertyHandle.java
* @throws SemanticException
	 *             if the position is out of range
	 */
	public void dropAndClear( int posn ) throws SemanticException
	{
		if ( propDefn.getTypeCode( ) == IPropertyType.ELEMENT_TYPE )
		{
			DesignElementHandle content = (DesignElementHandle) get( posn );
			dropAndClear( content );
		}
		else
		{
			removeItem( posn );
		}
	}
	/**
	 * Drops a content element at the given position from the slot, and
	 * unresolve any reference property which refers the element to drop.
	 * 
	 * @param posn
	 *            the position of the content to drop
	 * @throws SemanticException
	 *             if the position is out of range
	 */
	public void drop( int posn ) throws SemanticException
	{
		if ( propDefn.isElementType( ) )
		{
			DesignElementHandle content = (DesignElementHandle) get( posn );
			drop( content );