class ActionDispatch::Request

def controller_class_for(name)
  if name
    controller_param = name.underscore
    const_name = controller_param.camelize << "Controller"
    begin
      const_name.constantize
    rescue NameError => error
      if error.missing_name == const_name || const_name.start_with?("#{error.missing_name}::")
        raise MissingController.new(error.message, error.name)
      else
        raise
      end
    end
  else
    PASS_NOT_FOUND
  end
end