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
Collections.sort( methods, comp );
		return methods;
	}
	public static List getMembers( IClassInfo classInfo )
	{
		return getMembers( classInfo, new AlphabeticallyComparator( ) );
	}
	public static List getMembers( IClassInfo classInfo, Comparator comp )
	{
		List members = classInfo.getMembers( );
		Collections.sort( members, comp );
		return members;
	}
	/**
	 * 
	 * Return DesignElementHandle avaliable method's argument type name.
	 * 
	 * @param handle
	 *            DesignElementHandle.
	 * @param methodName
	 * @param argIdex
	 *            starts from 0.
	 * @return
	 */
	public static String getMethodArgumentType( DesignElementHandle handle,
			String methodName, int argIndex )
	{
		if ( handle instanceof DataSetHandle )
			return "DataSet";
		if ( handle instanceof DataSourceHandle )