DietCake Exercises

I think this is fine po :bow:
```php
if(!$this->validate()) {
    throw new ValidationException("invalid inputs");
}

$input = array(
    'nickname' => $this->nickname,
    'username' => $this->username, 
    'password' => sha1($this->password), //sha1 mysql encription
    'email' => $this->email,
);
```