import { Observable } from 'rxjs';
export interface ColumnStorage {
    tableId: string;
    visibleColumns: string[];
}
export declare class ColumnStorageService {
    dbName: string;
    storeName: string;
    version: number;
    db: any;
    objectStore: any;
    constructor();
    isDbOpen(): boolean;
    save(doc: ColumnStorage): void;
    read(tableId: string): Observable<ColumnStorage>;
}