It is not required by default when you set the property "when"

This function is used here:

`ActiveField.php`
```PHP
if ($this->model->isAttributeRequired($attribute)) {
    $class[] = $this->form->requiredCssClass;
}
```

However, when we condition the validation, I understand that, in principle, the field is not required until such condition is true.

My thinking is correct?