https://api.drupal.org/api/drupal/core%21modules%21migrate_drupal_ui%21tests%21src%21Functional%21MigrateUpgradeTestBase.php/property/MigrateUpgradeTestBase%3A%3AdestinationSiteVersion/10
MigrateUpgradeTestBase::$destinationSiteVersion | Drupal API
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