How to use groupBy in sailsJs Waterline Query Language

I am using groupBy in sailsJs Waterline Query Language but getting error.

Error :- "AdapterError: Cannot groupBy without a calculation"

Code :-

var options = {
          groupBy: ['name']
        };

Model.find(options)
        .then(function (rows) {
    ......
    }

via Sanjeev