    # File lib/fog/ibm/requests/compute/modify_instance.rb, line 39
            def modify_instance(instance_id, params={})
              response = Excon::Response.new
              if instance_exists? instance_id
                if params['state'] == 'restart'
                  self.data[:instances][instance_id]["status"] = "8"
                  response.status = 200
                  response.body   = { "success" => true }
                elsif params['type'] == 'attach' || params['type'] == 'detach'
                  if Fog::Storage[:ibm].volume_exists?(params['volume_id'])
                    # TODO: Update the instance in the data hash, assuming IBM ever gets this feature working properly.
                    response.status = 415
                  else
                    response.status = 404
                  end
                elsif params['name']
                  self.data[:instances][instance_id]["name"] = params['name']
                  response.status = 200
                  response.body = { "success" => true }
                elsif params['expirationTime']
                  self.data[:instances][instance_id]["expirationTime"] = params['expirationTime']
                  response.status = 200
                  response.body = { 'expirationTime' => params['expirationTime'] }
                end
              else
                response.status = 404
              end
              response
            end