/**
 * 返回变量名称
 *
 * ```ts
 * import { varName } from 'sunny-js'
 * const variable = undefined
 * console.log(varName({ variable }))
 * // => 'variable'
 * console.log(varName({ [variable]: undefined }))
 * // => 'variable'
 * ```
 *
 */
export declare function varName<TObj extends Record<string | number, any>>(obj: TObj): keyof TObj;