You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: model_actor.rb
    path of file: ./repos/hyrax/app/actors/hyrax/actors
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
module Hyrax
  module Actors
    # This is a proxy for the model specific actor
    class ModelActor < AbstractActor
      # See: https://github.com/bbatsov/rubocop/issues/5393
      
    
      def model_actor(env)
        actor_identifier = env.curation_concern.class
        klass = "Hyrax::Actors::#{actor_identifier}Actor".constantize
        klass.new(next_actor)
      rescue NameError => error
        Hyrax.logger.info 'No ModelActor provided for ' \
                          "#{env.curation_concern.class}; falling back on " \
                          "NullActor\n\t#{error}"

        NullActor.new(next_actor)
      end