Validator Recognises null in 'notEmptyString'

In the docs, it says a null key-presence is counted as valid. Is there a way to check for null values ? Maybe something like notNullValue option in the validator ?

Key presence is checked by using array_key_exists() so that null values will count as present. You can set the mode using the second parameter:

Problem example :

// in src/Modal/Table/xx.php

            ->requirePresence('working_status', true )

After creating an entity (newEntity), there are errors reported by the entity. Once I set the field to null, the error disappears even though notEmptyString is in the validator.

// To simplify stuff. A simple array
// Error will be reported by entity ([hasErrors] => true)
$newEntity = $this->Users->newEntity([
  'working_status' => null

// No error will be reported by entity after setting it to null ([hasErrors] => false)
$newEntity->working_status = null;

I believe that validation is not checked at all when you do direct assignment to properties, only when you patch the entity.