Implements hook_query_TAG_alter() for tag 'efq_table_prefixing_test'.
Drupal\system\Tests\Entity\EntityFieldQueryTest::testTablePrefixing()
function field_test_query_efq_table_prefixing_test_alter(&$query) {
// Add an additional join onto the entity base table. This will cause an
// exception if the EFQ does not properly prefix the base table.
$query
->join('test_entity', 'te2', '%alias.ftid = test_entity.ftid');
}