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
ReportDesignConstants.PARAMETER_GROUP_ELEMENT ) );
	}
	/**
	 * @return Alphabetically sortted styles list.
	 */
	public static Iterator getStyles( )
	{
		return getStyles( new AlphabeticallyComparator( ) );
	}
	/**
	 * @param comparator
	 * @return return styles list sortted with given comparator.
	 */
	public static Iterator getStyles( Comparator comparator )
	{
		List styles = SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( ).getAllStyles( );
		Object[] stylesArray = styles.toArray( );
		if ( comparator != null )
		{
			Arrays.sort( stylesArray, comparator );
		}
		return Arrays.asList( stylesArray ).iterator( );
	}
	/**
	 * Checks if two strings have same value.
	 * 
	 * @param str1
	 * @param str2
	 * @return