TYPO3: select's with null options

// ext_tables.sql
CREATE TABLE tx_xxxxxxx_domain_model_record (
  ...
	type int(11) unsigned DEFAULT '0',
  ...
);

// TCA
        'type' => [
            'exclude' => false,
            'label' => 'LLL:EXT:xxxxxxx/Resources/Private/Language/locallang_db.xlf:xxxxx.type',
            'config' => [
                'type' => 'select',
                'renderType' => 'selectSingle',
                'default' => 0, // necessary for TYPO3 to allow the null-option
                'items' => [
                    ['', 0], // null-option
                ],
                'foreign_table' => 'tx_xxxxxx_domain_model_type',
                'minitems' => 0,
                'maxitems' => 1,
            ],
        ],