Bug 167542 A parameter group isn't deleted after moving it to another parameter group through DND
Drag a parameter group and drop it to another one is a "move" operation, which cuts the source and pastes to the destination. But the source one isn't deleted in such operation while the parameters in the group are all deleted.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DNDUtil.java
}
	protected static int handleValidateTargetCanContainElementHandle(
			DesignElementHandle targetHandle, DesignElementHandle childHandle,
			boolean validateContainer )
	{
		if ( targetHandle instanceof CascadingParameterGroupHandle )
		{
			return childHandle.getContainer( ) == targetHandle ? CONTAIN_THIS
					: CONTAIN_NO;
		}
		else if ( targetHandle.canContain( DEUtil.getDefaultSlotID( targetHandle ),
				childHandle ) )
		{
			return CONTAIN_THIS;
		}
		else if ( targetHandle instanceof ParameterGroupHandle
				&& childHandle instanceof ParameterGroupHandle )
		{
			return CONTAIN_THIS;
		}
		else if ( targetHandle instanceof ReportDesignHandle
				&& childHandle instanceof ThemeHandle )
		{
			return CONTAIN_THIS;
		}