@Override
	public void markupItemSelected(VTMarkupItem markupItem) {
		if (sourceHighlightProvider != null) {
			sourceHighlightProvider.setMarkupItem(markupItem);
		}
		if (destinationHighlightProvider != null) {
			destinationHighlightProvider.setMarkupItem(markupItem);
		}
	}
Determines whether or not the dual listing is currently being shown to the user.
@return true if the dual listing is showing
Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/provider/markuptable/VTMarkupItemsTableProvider.java