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: token_extractor.rb
    path of file: ./repos/open-build-service/src/api/app/services/trigger_controller_service
    
    the code of the file until where you have to start completion: module TriggerControllerService
  class 
    
    def extract_auth_token_from_headers
      auth_token = @http_request.env['HTTP_X_GITLAB_TOKEN'] ||
                   extract_token_string_from_authorization_header

      return unless auth_token

      Token.find_by_string!(auth_token) if auth_token.match?(%r{^[A-Za-z0-9+/]+$})
    end