# File lib/fog/aws/requests/compute/modify_volume_attribute.rb, line 35
        def modify_volume_attribute(volume_id=nil, auto_enable_io_value=false)
          response = Excon::Response.new
          if volume = self.data[:volumes][volume_id]
            response.status = 200
            response.body = {
              'requestId' => Fog::AWS::Mock.request_id,
              'return'    => true
            }
            response
          else
            raise Fog::Compute::AWS::NotFound.new("The volume '#{volume_id}' does not exist.")
          end
        end