6 files declare their use of DeriverInterface in Drupal 9
- ContainerDeriverInterface.php in core/
lib/ Drupal/ Core/ Plugin/ Discovery/ ContainerDeriverInterface.php - MockLayoutBlockDeriver.php in core/
modules/ system/ tests/ modules/ plugin_test/ src/ Plugin/ plugin_test/ mock_block/ MockLayoutBlockDeriver.php - MockMenuBlockDeriver.php in core/
modules/ system/ tests/ modules/ plugin_test/ src/ Plugin/ plugin_test/ mock_block/ MockMenuBlockDeriver.php - TestDerivativeDiscovery.php in core/
tests/ Drupal/ Tests/ Core/ Plugin/ Discovery/ TestDerivativeDiscovery.php - TestDerivativeDiscoveryWithObject.php in core/
tests/ Drupal/ Tests/ Core/ Plugin/ Discovery/ TestDerivativeDiscoveryWithObject.php - TestHelpTopicDeriver.php in core/
modules/ help_topics/ tests/ modules/ help_topics_test/ src/ Plugin/ Deriver/ TestHelpTopicDeriver.php