Without this fix we can not set type of hasOne field and as result typecasting treat hasOne field as type=null always. This is bad if we want id field to be integer to avoid trying to insert empty string value instead of NULL in id field.
Without this fix we can not set type of hasOne field and as result typecasting treat hasOne field as type=null always. This is bad if we want id field to be integer to avoid trying to insert empty string value instead of NULL in id field.

Example,
```
$this->hasOne('contact_id', [
    'Contact',
    'type' => 'integer', // setting this had no effect up till now
]);
```

atk4/data