isWeakMap 
Checks if the given value is a WeakMap.
This function tests whether the provided value is an instance of WeakMap. It returns true if the value is a WeakMap, and false otherwise.
This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to WeakMap.
Signature 
typescript
function isWeakMap(value: unknown): value is WeakMap<WeakKey, any>;Parameters 
value (unknown): The value to test if it is a WeakMap.
Returns 
(value is WeakMap<WeakKey, any>): true if the value is a WeakMap, false otherwise.
Examples 
typescript
const value1 = new WeakMap();
const value2 = new Map();
const value3 = new Set();
console.log(isWeakMap(value1)); // true
console.log(isWeakMap(value2)); // false
console.log(isWeakMap(value3)); // false
