Bug 167545 Copy a cascading parameter group and paste it to another parameter group causes an exception thrown
Steps to reproduce: 1.Copy a cascading parameter group using short cut key "Ctrl+x"/"Ctrl+c", or choosing context menu "Cut"/"Copy"; 2.Paste it to another parameter group using short cut key "Ctrl+v", or choosing context menu "Paste"; Expected result: The source one is pasted in the destination. Actual result: An exception thrown org.eclipse.birt.report.model.api.command.ContentException: The Cascading Parameter Group("Source") is not allowed in the slot (parameters) of Parameter Group("Destination").
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
/**
	 * Transform other units to target unit.
	 * 
	 * @param handle
	 * @param targetUnit
	 * @return
	 */
	public static double convertToValue( DimensionHandle handle,
			String targetUnit )
	{
		double retValue = 0.0;
		if ( handle.isSet( ) )
		{
			retValue = DimensionUtil.convertTo( handle.getMeasure( ),
					handle.getUnits( ),
					targetUnit ).getMeasure( );
		}
		return retValue;
	}
	/**
	 * Checks if the value can be converted to a valid Integer.
	 * 
	 * @param val
	 * @return true if the value can be converted to a valid Integer, else
	 *         false.
	 */
	public static boolean isValidInteger( String val )
	{
		try
		{