 
     @objc private func cancelComparison(_ sender: UIBarButtonItem?) {
         state = .idle
-    }
-
-    private func resetComparisonSelectionButtons() {
-        firstComparisonSelectionButton.setTitle(nil, for: .normal)
-        firstComparisonSelectionButton.setImage(nil, for: .normal)
-        secondComparisonSelectionButton.setTitle(nil, for: .normal)
-        secondComparisonSelectionButton.setImage(nil, for: .normal)
-        firstComparisonSelectionButton.backgroundColor = theme.colors.paperBackground
-        secondComparisonSelectionButton.backgroundColor = theme.colors.paperBackground
-    }
-
-    @objc private func tappedCompare(_ sender: UIBarButtonItem) {
-        guard let firstIndexPath = indexPathsSelectedForComparisonGroupedByButtonTags[0], let secondIndexPath = indexPathsSelectedForComparisonGroupedByButtonTags[1] else {
-            return
-        }
-        let revision1 = pageHistorySections[firstIndexPath.section].items[firstIndexPath.item]
-        let revision2 = pageHistorySections[secondIndexPath.section].items[secondIndexPath.item]
-        
-        guard let date1 = revision1.revisionDate,
-            let date2 = revision2.revisionDate else {
-                return
-        }
-        
-        //show older revision as "from" no matter what order was selected
-        let fromRevision: WMFPageHistoryRevision
-        let toRevision: WMFPageHistoryRevision
-        if date1.compare(date2) == .orderedAscending {
-            fromRevision = revision1
-            toRevision = revision2
-        } else {
-            fromRevision = revision2
-            toRevision = revision1
-        }
-        
-        showDiff(from: fromRevision, to: toRevision, type: .compare(articleTitle: pageTitle))
     }
     
     private func showDiff(from: WMFPageHistoryRevision, to: WMFPageHistoryRevision, type: DiffContainerViewModel.DiffType) {

                    cell.enableEditing(false)
                }
            }
            switch openSelectionIndex {
            case 0:
                button = firstComparisonSelectionButton
                themeModel = firstSelectionThemeModel
            case 1:
                button = secondComparisonSelectionButton
                themeModel = secondSelectionThemeModel
            default:
                button = nil
                themeModel = nil
            }
            if let button = button, let themeModel = themeModel {
                updateComparisonButton(button, with: themeModel, cell: cell)
                indexPathsSelectedForComparisonGroupedByButtonTags[button.tag] = indexPath
            }
            updateSelectionIndex(openSelectionIndex, for: cell, at: indexPath)
            updateSelectionThemeModel(themeModel, for: cell, at: indexPath)
            openSelectionIndex += 1

            collectionView.reloadData()
        } else {
            let cell = collectionView.cellForItem(at: indexPath)
            cell?.isSelected = false

        navigationItem.rightBarButtonItem?.tintColor = theme.colors.link
        navigationItem.leftBarButtonItem?.tintColor = theme.colors.primaryText
        countsViewController.apply(theme: theme)
        comparisonSelectionViewController.apply(theme: theme)
    }

    // MARK: UICollectionViewDataSource
