PreviewFallbackInterface

class \Drupal\Core\Block\BlockBase extends \Drupal\Core\Block\BlockPluginInterface, \Drupal\Core\Plugin\PluginWithFormsInterface, \Drupal\Core\Plugin\PreviewAwarePluginInterface, \Drupal\Core\Render\PreviewFallbackInterface, \Drupal\Core\Plugin\ContextAwarePluginInterface uses \Drupal\Core\Block\BlockPluginTrait, \Drupal\Core\Plugin\ContextAwarePluginTrait, \Drupal\Core\Plugin\ContextAwarePluginAssignmentTrait implements \Drupal\Core\Plugin\PluginBase
class \Drupal\Core\Block\Plugin\Block\PageTitleBlock extends \Drupal\Core\Block\TitleBlockPluginInterface implements \Drupal\Core\Block\BlockBase
class \Drupal\Core\Menu\Plugin\Block\LocalActionsBlock extends \Drupal\Core\Plugin\ContainerFactoryPluginInterface implements \Drupal\Core\Block\BlockBase
class \Drupal\Core\Menu\Plugin\Block\LocalTasksBlock extends \Drupal\Core\Plugin\ContainerFactoryPluginInterface implements \Drupal\Core\Block\BlockBase
class \Drupal\block_example\Plugin\Block\ExampleConfigurableTextBlock implements \Drupal\Core\Block\BlockBase
class \Drupal\block_example\Plugin\Block\ExampleEmptyBlock implements \Drupal\Core\Block\BlockBase
class \Drupal\block_example\Plugin\Block\ExampleUppercaseBlock implements \Drupal\Core\Block\BlockBase
class \Drupal\ctools\Plugin\Block\EntityView extends \Drupal\Core\Plugin\ContextAwarePluginInterface, \Drupal\Core\Plugin\ContainerFactoryPluginInterface implements \Drupal\Core\Block\BlockBase
class \Drupal\ctools_block\Plugin\Block\EntityField extends \Drupal\Core\Plugin\ContextAwarePluginInterface, \Drupal\Core\Plugin\ContainerFactoryPluginInterface implements \Drupal\Core\Block\BlockBase
class \Drupal\devel\Plugin\Block\SwitchUserBlock extends \Drupal\Core\Plugin\ContainerFactoryPluginInterface uses \Drupal\Core\Routing\RedirectDestinationTrait implements \Drupal\Core\Block\BlockBase
class \Drupal\form_api_example\Plugin\Block\SimpleFormBlock extends \Drupal\Core\Plugin\ContainerFactoryPluginInterface implements \Drupal\Core\Block\BlockBase

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