Bug: singlestat panel and series with no data points

[HallsHalls]

response data:

[{"metric":"name","tags":{"cluster":"xxxx","running":"0","Hostname":"xxxx"},"aggregateTags":[],"dps":{}}]

and the JS ERROR

/single stat/module.js

Line:189 :
var lastValue = _.last($scope.series[0].datapoints)[0];
// dps is null that will be error

I suggest to fix this by add judge