src/vs/workbench/contrib/mergeEditor/browser/commands/commands.ts/ShowHideBase/constructor
class ShowHideBase:	constructor() {
		super({
			id: 'merge.showBase',
			title: {
				value: localize('layout.showBase', 'Show Base'),
				original: 'Show Base',
			},
			toggled: ctxMergeEditorShowBase.isEqualTo(true),
			menu: [
				{
					id: MenuId.EditorTitle,
					when: ContextKeyExpr.and(ctxIsMergeEditor, ctxMergeEditorLayout.isEqualTo('columns')),
					group: '2_merge',
					order: 9,
				},
			]
		});
	}