src/vs/platform/undoRedo/common/undoRedoService.ts/UndoRedoService/redo
class UndoRedoService:	public redo(resourceOrSource: URI | UndoRedoSource | string): Promise<void> | void {
		if (resourceOrSource instanceof UndoRedoSource) {
			const [, matchedStrResource] = this._findClosestRedoElementWithSource(resourceOrSource.id);
			return matchedStrResource ? this._redo(matchedStrResource) : undefined;
		}
		if (typeof resourceOrSource === 'string') {
			return this._redo(resourceOrSource);
		}
		return this._redo(this.getUriComparisonKey(resourceOrSource));
	}