PlaceholderStrategyInterface

class \Drupal\Core\Render\Placeholder\ChainedPlaceholderStrategy implements \Drupal\Core\Render\Placeholder\PlaceholderStrategyInterface
class \Drupal\Core\Render\Placeholder\SingleFlushStrategy implements \Drupal\Core\Render\Placeholder\PlaceholderStrategyInterface
class \Drupal\big_pipe\Render\Placeholder\BigPipeStrategy implements \Drupal\Core\Render\Placeholder\PlaceholderStrategyInterface

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