export type Animation = (params: { deltaTime: number; state?: R; }) => R | null | undefined; export declare class AnimationController { private static scheduledFrame; private static animations; static start(key: string, animation: Animation): void; private static scheduleNextFrame; private static cancelScheduledFrame; private static cancelScheduledFrameIfIdle; private static tick; static running(key: string): boolean; static cancel(key: string): void; static reset(): void; }