src/vs/workbench/contrib/mergeEditor/browser/view/mergeEditor.ts/MergeEditorLayoutStore/constructor
class MergeEditorLayoutStore:	constructor(@IStorageService private _storageService: IStorageService) {
		const value = _storageService.get(MergeEditorLayoutStore._key, StorageScope.PROFILE, 'mixed');

		if (value === 'mixed' || value === 'columns') {
			this._value = { kind: value, showBase: false, showBaseAtTop: true };
		} else if (value) {
			try {
				this._value = JSON.parse(value);
			} catch (e) {
				onUnexpectedError(e);
			}
		}
	}