docs: def ready(self):
          """Perform application initialization."""
          # Initialize the type extension composer.
          from . composer import composer
          composer.discover_extensions()
  
          is_migrating = sys.argv[1:2] == ['migrate']
          if is_migrating:
              # Do not register signals and ES indices when:
              # * migrating - model instances used during migrations do
              #   not contain the full functionality of models and things
              #   like content types don't work correctly and signals are
              #   not versioned so they are guaranteed to work only with
              #   the last version of the model
              return
  
          # Connect all signals
          from . import signals  # pylint: disable=unused-import
  
          # Register ES indices
          from . builder import index_builder