text: describe('BankAccount', function() {
    it('creates a new account and returns 0 balance', function() {
      var testAccount = Object.create(BankAccount);
      expect(testAccount.balance).to.equal(0);
    })
  
    describe('withdraw', function() {
      it('takes 5 and returns -5', function() {
        var testAccount = Object.create(BankAccount);
        testAccount.withdraw(5);
        expect(testAccount.balance).to.equal(-5);
      });
    });
  
    describe('deposit', function() {
      it('takes 5 and returns 5', function() {
        var testAccount = Object.create(BankAccount);
        testAccount.deposit(5);
        expect(testAccount.balance).to.equal(5);
      });
    });
  });
  