Warning: Assigning helper with `Template.backend.chartBackend = ...` is deprecated

[markshust]

I'm receiving this error with Meteor 1.1.0.2:

W20150719-08:25:11.512(-4) (blaze.js:71) Warning: Assigning helper with `Template.backend.chartBackend = ...` is deprecated.  Use `Template.backend.helpers(...)` instead.

However, when I change format to Template.backend.helpers format, I receive this error:

Exception from Tracker afterFlush function:
TypeError: null is not an object (evaluating 'options.chart')
highcharts@http://localhost:3000/packages/maazalik_highcharts.js?63886d2fa45cba023ed261d763e5628418c655fb:1021:30

[dpatte]

I had the same issue, but found that when I converted it to a helper, I had returned a null because my formatting looked like this
return
[