text: import Uniq from '../../src/uniq/uniq.main';
  
  describe('isProperSupersetOf', () => {
    test('should throw TypeError for invalid arguments', () => {
      const isProperSupersetOf = Uniq.prototype.isProperSupersetOf;
      expect(() => isProperSupersetOf.call(null, new Uniq())).toThrow(TypeError);
      expect(() => isProperSupersetOf.call(new Uniq(), null)).toThrow(TypeError);
    });
  
    test('should return correct result', () => {
      const s1 = Uniq.of(1, 3, 5, 4);
      const s2 = Uniq.of(1, 5);
      expect(s1.isProperSupersetOf(s2)).toBe(true);
      expect(Uniq.of().isProperSupersetOf(Uniq.of())).toBe(false);
      expect(Uniq.prototype.isProperSupersetOf.call(s1, s2)).toBe(true);
  
      expect(Uniq.of(1, 2, 3).isProperSupersetOf(Uniq.of(1, 2, 3))).toBe(false);
    });
  });
  