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
{
		
		if ( element == null )
		{
			SlotHandle slotHandle = parent.getSlot( DEUtil.getDefaultSlotID( parent ) );
			if ( slotHandle != null )
			{
				return slotHandle.getCount( );
			}
			return -1;
		}
		return DEUtil.findPos( parent, element.getContainerSlotHandle( )
				.getSlotID( ), element );
	}
	/**
	 * Map GUI defined property key to DE defined property key
	 * 
	 * @param key
	 * @return DE defined property key
	 */
	public static String getGUIPropertyKey( String key )
	{
		if ( key != null )
		{
			return (String) propertiesMap.get( key );
		}
		return null;
	}
	/**
	 * Transform other units to pixel.