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
childHandle,
					validateContainer );
		}
		if ( targetObj instanceof SlotHandle )
		{
			SlotHandle targetHandle = (SlotHandle) targetObj;
			return targetHandle.getElementHandle( )
					.canContain( targetHandle.getSlotID( ), childHandle ) ? CONTAIN_THIS
					: CONTAIN_NO;
		}
		return CONTAIN_NO;
	}
	protected static int handleValidateTargetCanContainByContainer(
			Object targetObj, Object[] childHandles, boolean validateContainer )
	{
		if ( childHandles.length == 0 )
		{
			return CONTAIN_NO;
		}
		for ( int i = 0; i < childHandles.length; i++ )
		{
			if ( !( childHandles[i] instanceof DesignElementHandle )
					|| handleValidateTargetCanContainByContainer( targetObj,
							(DesignElementHandle) childHandles[i],
							validateContainer ) == CONTAIN_NO )
			{
				return CONTAIN_NO;
			}
		}
		return CONTAIN_THIS;