The theme handler. Type:

public Block::getRegion() Returns the

public BlockViewBuilder::viewMultiple(array $entities = array()

public BlockController::demo($theme)

The theme manager. Type:

public Block::setVisibilityConfig($instance_id, array $configuration)

Denotes that a block is not enabled in any region and should not be shown. File core/modules/block/src/BlockInterface

public BlockViewBuilder::__construct(EntityTypeInterface $entity_type

The block storage. Type:

public BlockController::__construct(ThemeHandlerInterface