Craft\Neo_BlockTypeRecord::defineRelations PHP Method

    public function defineRelations()
    {
        return ['field' => [static::BELONGS_TO, 'FieldRecord', 'required' => true, 'onDelete' => static::CASCADE], 'fieldLayout' => [static::BELONGS_TO, 'FieldLayoutRecord', 'onDelete' => static::SET_NULL]];
    }