import { Ref, KeyTypeConstraints } from './types'; export declare function uuidv4(): string; export declare const randomListLength: () => number; export declare const takeRandom: (arr: T[]) => T; export declare function makeRef(typeName: string, key: KeyT): Ref; export declare function isObject(thing: any): boolean; export declare function copyOwnPropsIfNotPresent(target: Record, source: Record): void; export declare function copyOwnProps(target: Record, ...sources: Array>): Record;