private ListingDiff buildListingDiff() {
		ListingDiff diff = new ListingDiff();
		diffActionManager = new ListingDiffActionManager(diff);
		return diff;
	}
Creates a comparison panel with two listings.

@param owner the owner of this panel
@param tool the tool displaying this panel
Ghidra/Features/Base/src/main/java/ghidra/features/base/codecompare/listing/ListingCodeComparisonPanel.java