docs: def handle(self, *args, **options):
          """Register processes."""
          force = options.get('force')
          retire = options.get('retire')
          verbosity = int(options.get('verbosity'))
  
          users = get_user_model().objects.filter(is_superuser=True).order_by('date_joined')
  
          if not users.exists():
              self.stderr.write("Admin does not exist: create a superuser")
              exit(1)
  
          process_paths, descriptor_paths = [], []
          process_schemas, descriptor_schemas = [], []
  
          for finder in get_finders():
              process_paths.extend(finder.find_processes())
              descriptor_paths.extend(finder.find_descriptors())
  
          for proc_path in process_paths:
              process_schemas.extend(
                  self.find_schemas(proc_path, schema_type=SCHEMA_TYPE_PROCESS, verbosity=verbosity))
  
          for desc_path in descriptor_paths:
              descriptor_schemas.extend(
                  self.find_schemas(desc_path, schema_type=SCHEMA_TYPE_DESCRIPTOR, verbosity=verbosity))
  
          user_admin = users.first()
          self.register_descriptors(descriptor_schemas, user_admin, force, verbosity=verbosity)
          # NOTE: Descriptor schemas must be registered first, so
          #       processes can validate 'entity_descriptor_schema' field.
          self.register_processes(process_schemas, user_admin, force, verbosity=verbosity)
  
          if retire:
              self.retire(process_schemas)
  
          if verbosity > 0:
              self.stdout.write("Running executor post-registration hook...")
          manager.get_executor().post_register_hook(verbosity=verbosity)