@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Employee employee = (Employee) o;

        if (id != employee.id) return false;
        if (firstName != null ? !firstName.equals(employee.firstName) : employee.firstName != null) return false;
        if (lastName != null ? !lastName.equals(employee.lastName) : employee.lastName != null) return false;

        return true;
    }