[question] Extend module types

It's a question that should be asked on SO, but I can't get a response there..

In a React Native app I am assigning a custom method to the `console` e.g. `console.foo = (string) => {}`. The console module type is already [defined here](https://github.com/facebook/react-native/blob/master/flow/console.js). So I get the error: `Property not found in object type`. How can I extend a console module with a custom method type?