import { ModelManipulator } from '../../manipulators/model-manipulator'; export declare abstract class HistoryItem { modelManipulator: ModelManipulator; uniqueId: number; canBeMerged(): boolean; constructor(modelManipulator: ModelManipulator); changeModified(): boolean; abstract redo(): any; abstract undo(): any; } export declare class CompositionHistoryItem extends HistoryItem { historyItems: HistoryItem[]; canBeMerged(): boolean; constructor(); changeModified(): boolean; redo(): void; undo(): void; add(historyItem: HistoryItem): void; }