export type PropertyName = string | number | symbol;
export type IterateeFunction<T> = (value: T) => PropertyName;
export type Iteratee<T> = IterateeFunction<T> | keyof T;
/**
 * Creates an object composed of keys generated from the results of running each element of collection through iteratee
 * @param collection The collection to iterate over
 * @param iteratee The iteratee function or property name to generate the key
 *
 * @remarks
 * **Prototype pollution warning:** This function does not filter out
 * prototype-polluting keys (`__proto__`, `constructor`, `prototype`).
 * If processing user-controlled input, sanitize with the appropriate
 * `removePrototype*` helper before calling this function:
 * - `removePrototype` — shallow sanitization of a single object
 * - `removePrototypeDeep` — recursive sanitization of a single object (for deeply nested data)
 * - `removePrototypeMap` — shallow sanitization of an array of objects
 * - `removePrototypeMapDeep` — recursive sanitization of an array of objects (for deeply nested data)
 */
export declare function keyBy<T>(collection: T[] | Record<PropertyName, T>, iteratee?: Iteratee<T>): Record<PropertyName, T>;