问左连接CakePHP3

EN

SELECT
 identities.id
FROM
 identities
LEFT JOIN borrowers ON borrowers.id = identities.id
WHERE
 borrowers.id IS NULL;

$var = $identities->find()->select(['identities.id'])->leftJoinWith('Borrowers',
        function ($q) {
               return $q->where(['borrowers.id' => 'identities.id']);
        });

$this->belongsTo('Borrowers', [
  'foreignKey' => 'id'
]);