All classes that implement CKEditorPluginContextualInterface

class \Drupal\ckeditor_test\Plugin\CKEditorPlugin\LlamaContextual implements CKEditorPluginContextualInterface
class \Drupal\ckeditor_test\Plugin\CKEditorPlugin\LlamaContextualAndButton implements CKEditorPluginButtonsInterface, CKEditorPluginConfigurableInterface, CKEditorPluginContextualInterface