JS Proxy Handler getPrototypeOf

The handler.getPrototypeOf() method is a trap for the[[GetPrototypeOf]] internal method. The following parameter is passed to the getPrototypeOf() method. this is bound to the handler. The getPrototypeOf() method must return an object or null. This trap can intercept these operations: If the following invariants are violated, the proxy will throw a : getPrototypeOf() method must return an object or null.