| undefined;
/**
* Returns the prototype of an object.
* @param target The object that references the prototype.
*/
function getPrototypeOf(target: object): object | null;
/**
* Equivalent to `propertyKey in target`.
* @param target Object that contains the property on itself or in its prototype chain.
* @param propertyKey Name of the property.
*/
function has(target: object, propertyKey: PropertyKey): boolean;
/**
* Returns a value that indicates whether new properties can be added to an object.
* @param target Object to test.
*/
function isExtensible(target: object): boolean;
/**
* Returns the string and symbol keys of the own properties of an object. The own properties of an object
* are those that are defined directly on that object, and are not inherited from the object's prototype.
* @param target Object that contains the own properties.
*/
function ownKeys(target: object): (string | symbol)[];
/**
* Prevents the addition of new properties to an object.
* @param target Object to make non-extensible.
* @return Whether the object has been made non-extensible.
*/
function preventExtensions(target: object): boolean;
/**
* Sets the property of target, equivalent to `target[propertyKey] = value` when `receiver === target`.
* @param target Object that contains the property on itself or in its prototype chain.
* @param propertyKey Name of the property.
* @param receiver The reference to use as the `this` value in the setter function,
* if `target[propertyKey]` is an accessor property.
*/
function set