Bad example in Medium poast

Medium isn't letting me comment, so posting here. The createDecorator example in this post throws "update is not a function" errors: https://blog.cloudboost.io/final-form-decorators-calculated-fields-and-warnings-bf9cccd21b7e

In the example, foo's "updates" field is an array but it looks like it needs to be an object. Thought you would like to know, I use the examples on those Medium posts all the time, thanks for all your work on this library!