Entity delete with java

public class JpaAccountDao implements AccountDao {

    @PersistenceContext(unitName = "account")
    private EntityManager entityManager;

    public JpaAccountDao() {
    }
    public JpaAccountDao(EntityManager entityManager){
        this.entityManager = entityManager;
    }

    @Override
    public Account persist(Account account) {
        if( account == null )
            throw new IllegalArgumentException("No account could be created!");
        entityManager.persist(account);
        return account;
    }

    @Override
    public Boolean delete(int id) {
        if( id != 0) {
            Account account = entityManager.find(Account.class,id);
            entityManager.remove(account);
            return true;
        }
        throw new IllegalArgumentException(String.format("Account with id-nr:{%d] could not be deleted =C ", id ));
    }
    @Override
    public Account findById(int id) {
        if( id <= 0 )
            throw new IllegalArgumentException("No id was found!");
        return entityManager.find(Account.class, id);
    }

    @Override
    public List<Account> getAll() {
        TypedQuery<Account> query = entityManager.createNamedQuery("Account.getAll", Account.class);
        return query.getResultList();
    }
}

@Entity
@SequenceGenerator(name = "SEQ_LOG", initialValue = 50)
public class Login {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_LOG")
    @Column(name = "FK_LOGIN")
    private int Id;
    @NotNull
    private String username;
    @NotNull
    private String password;

    public Login(String username, String password) {
        this.username = username;
        this.password = password;
    }
    public Login(){

    }
    public int getId() {
        return Id;
    }
    public void setId(int id) {
        Id = id;
    }
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "Login{" +
                "Id=" + Id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

@Entity
@NamedQuery(name = "Customer.getAll", query = "SELECT c FROM Customer c")
@SequenceGenerator(name = "SEQ_CUST", initialValue = 50)
public class Customer {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_CUST")
    @Cascade(CascadeType.DETACH)
    @Column(name = "FK_CUSTOMER")
    private int id;
    @NotNull
    private String firstName;
    @NotNull
    private String lastName;
    @NotNull
    private String email;
    @NotNull
    private String phoneNumber;
    @NotNull
    private Date birth;

    @OneToOne(fetch = FetchType.EAGER, orphanRemoval = true)
    @JoinColumn(name = "FK_Account")
    private Account account;

    public Customer(){
    }

    public Customer(String firstName, String lastName, String email, String phoneNumber, Date birth) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
        this.phoneNumber = phoneNumber;
        this.birth = birth;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public Date getBirth() {
        return birth;
    }

    public void setBirth(Date birth) {
        this.birth = birth;
    }
    @Override
    public String toString() {
        return "Customer{" +
                "customerId=" + id +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", email='" + email + '\'' +
                ", phoneNumber='" + phoneNumber + '\'' +
                ", birth=" +  birth +
                '}';
    }
}


@Entity
@NamedQuery(name = "Account.getAll", query = "select a from Account a")
@SequenceGenerator(name = "SEQ_ACC", initialValue = 50)
public class Account {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_ACC")
    private int id;

    @OneToOne(cascade = CascadeType.ALL)//, fetch = FetchType.EAGER)
    @JoinColumn(name = "FK_CUSTOMER")
    private Customer customer;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "FK_LOGIN")
    private Login login;

    public Account(Customer customer, Login login) {
        this.customer = customer;
        this.login = login;
    }

    public Account() {

    }
    public Customer getCustomer() {
        return customer;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public void setCustomer(Customer customer) {
        this.customer = customer;
    }

    public Login getLogin() {
        return login;
    }

    public void setLogin(Login login) {
        this.login = login;
    }
    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", customer=" + customer +
                ", login= '" + login +
                '}';
    }
}

public class AccountServiceIT {
    private EntityManager entityManager;
    private EntityManagerFactory factory;
    private JpaAccountDao jpaAccountDao;
    private JpaCustomerDao jpaCustomerDao;
    private CustomerTestCase customerTestCase;
    private JpaLoginDao jpaLoginDao;
    private Account account;
    private Account account2;

    @Before
    public void setup() throws Exception {
        factory = Persistence.createEntityManagerFactory("TEST");
        entityManager = factory.createEntityManager();
        jpaAccountDao = new JpaAccountDao(entityManager);
   //     customerTestCase = new CustomerTestCase();
     //   jpaCustomerDao = customerTestCase.setup();


        account = new Account();
        account2 = new Account();
    }
    @After
    public void tearDown() throws Exception {
        entityManager.close();
        factory.close();
    }
  @Test
    public void deleteAccountTest() throws Exception {
        Account account = entityManager.find(Account.class, 1);
        entityManager.getTransaction().begin();
        boolean result = jpaAccountDao.delete(account.getId());
        entityManager.getTransaction().commit();

        Account res = jpaAccountDao.findById(1);
        assertEquals(res, account);
        assertNull(result);
    }
}