Bug 120503 Cascading Parameter can not drop into layout
Details: Cascading Parameter can not drop into layout Step: 1.Open a report design and Create a Sample Data Source and data set by "select * from CLASSICMODELS.CUSTOMERS" 2.New a cascading parameter and create CUSTOMERSNUMBER and CUSTOMERSNAME in parameter named number and name. Press OK 3.Drop parameter name into layout. Actual results: The parameter in Cascading Parameter Group can not drop to layout
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
return new GroupElementHandle( SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( ), modelList );
	}
	/**
	 * Checks if the library is included.
	 * 
	 * @param handle
	 * @return
	 */
	public static boolean isIncluded( LibraryHandle handle )
	{
		return handle.getNamespace( ) != null;
	}
	public static List getClasses( )
	{
		return getClasses( new AlphabeticallyComparator( ) );
	}
	public static List getClasses( Comparator comp )
	{
		List classes = DesignEngine.getMetaDataDictionary( ).getClasses( );
		Collections.sort( classes, comp );
		return classes;
	}
	public static List getMethods( IClassInfo classInfo )
	{
		return getMethods( classInfo, new AlphabeticallyComparator( ) );
	}
	public static List getMethods( IClassInfo classInfo, Comparator comp )
	{
		List methods = classInfo.getMethods( );