text: test("length is 1", () => {
      expect(Set.prototype.has).toHaveLength(1);
  });
  
  test("basic functionality", () => {
      var set = new Set(["hello", "friends", 1, 2, false]);
  
      expect(new Set().has()).toBeFalse();
      expect(new Set([undefined]).has()).toBeTrue();
      expect(set.has("hello")).toBeTrue();
      expect(set.has(1)).toBeTrue();
      expect(set.has("serenity")).toBeFalse();
  });
  