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
SlotHandle groupSlotHandle = ( (ListingHandle) handle ).getGroups( );
			for ( Iterator iter = groupSlotHandle.iterator( ); iter.hasNext( ); )
			{
				GroupHandle group = (GroupHandle) iter.next( );
				groupList.add( group );
			}
			return groupList;
		}
		DesignElementHandle result = handle.getContainer( );
		if ( result != null )
		{
			if ( result instanceof GroupHandle )
			{
				groupList.add( result );
				return groupList;
			}
			return getGroups( result );
		}
		return groupList;
	}
	/**
	 * The group container is ListingHandler, list, table, and so on.
	 */
	public static final String TYPE_GROUP_LISTING = "listing";
	/**
	 * The group container is GroupHandler
	 */
	public static final String TYPE_GROUP_GROUP = "group";
	/**
	 * other container, has none group.