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: retrieve_topic.rb
    path of file: ./repos/discourse/app/jobs/regular
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Jobs
  # Asynchronously retrieve a topic from an embedded site
  class RetrieveTopic < ::Jobs::Base
    def execute(args)
      raise Discourse::InvalidParameters.new(:embed_url) unl
    
    def execute(args)
      raise Discourse::InvalidParameters.new(:embed_url) unless args[:embed_url].present?

      user = nil
      user = User.find_by(id: args[:user_id]) if args[:user_id]
      TopicRetriever.new(
        args[:embed_url],
        author_username: args[:author_username],
        no_throttle: user.try(:staff?),
      ).retrieve
    end