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: helpers.rb
    path of file: ./repos/kontena/server/app/mutations/grid_services
    
    the code of the file until where you have to start completion: module GridServices
  module Helpers
    include Logging

    # List changed fields of model
   
    
    def update_grid_service(grid_service, force: false)
      if grid_service.changed? || force
        grid_service.revision += 1
        info "updating service #{grid_service.to_path} revision #{grid_service.revision} with changes: #{document_changes(grid_service)}"
      else
        debug "not updating service #{grid_service.to_path} revision #{grid_service.revision} without changes"
      end