code: function(args) {
                  
                  var x = _.isFinite(args.x) ? args.x : 2;
  
                  return _.template('<filter><feGaussianBlur stdDeviation="${stdDeviation}"/></filter>', {
                      stdDeviation: _.isFinite(args.y) ? [x, args.y] : x
                  });
              }
docs: `x` ... horizontal blur `y` ... vertical blur (optional)