It should be possible to transfer some shares to another user

index.ts

it("It should be possible to transfer some shares to another user", async () => {
    const Apartment = await ethers.getContractFactory("Apartment");
    const apartment = await Apartment.deploy();

    [owner, Alice] = await ethers.getSigners();

    await apartment.deployed();
    await apartment.transfer(Alice.address, 20);
    expect(await apartment.balanceOf(Alice.address)).to.equal(20);
    expect(await apartment.balanceOf(owner.address)).to.equal(80);
  })