export interface DBCoreCursor {
readonly trans: DBCoreTransaction;
readonly key: any;
readonly primaryKey: any;
readonly value?: any;
readonly done?: boolean;
continue(key?: any): void;
continuePrimaryKey(key: any, primaryKey: any): void;
advance(count: number): void;
start(onNext: ()=>void): Promise<any>
stop(value?: any | Promise<any>): void;
next(): Promise<DBCoreCursor>;
fail(error: Error): void;
}