export declare class LayoutContentCache {
    private contentItemCache;
    private contentItemCacheId;
    private createCacheKey;
    hasKey: (id: string) => boolean;
    getItemOrUndefined: (id: string) => GoldenLayout.ContentItem | undefined;
    getContentItemOrThrow: (id: string, expectedType?: string[]) => GoldenLayout.ContentItem;
    getOrCreateEntityId: (contentItem: GoldenLayout.ContentItem) => string;
}