text: const expect = require('expect');
  const utils = require('./utils');
  it('should add two numbers', () => {
    let res = utils.add(12, 28);
    expect(res).toBe(40).toBeA('number');
  });
  
  it('square the number', () => {
    let res = utils.square(3);
    expect(res).toBe(9).toBeA('number');
  });
  
  it('testing', () => {
    expect(10).toNotBe(11);
    expect([1,2,3]).toInclude(1);
    expect({animal: "dog"}).toNotEqual({animal: "cat"});
    expect({a: '1', b: '2', c: '3'}).toInclude({b: '2'});
  });
  
  it('first name and last name should be correct', () => {
    let user = { place: "Serbia", name: "Bob" };
    let res = utils.setName(user, "John Wick");
    expect(user).toInclude({ lastName: "Wick", firstName: "John" });
  });
  
  it('async add', (done) => {
    utils.sumAsync(4, 3, (sum) => {
      expect(sum).toBe(7).toBeA('number');
      done();
    });
  });
  