Confusing naming of function passed to Array.map

Hello,
not a real issue but just a naming of a method that confused me for a bit.
In [datasource/launch](https://github.com/apollographql/fullstack-tutorial/blob/master/final/server/src/datasources/launch.js#L10) there is method called `launchReducer` passed to `Array.map`. This method is responsible to take each launch returned by the Rest API and **mapping** it to another object.
So I guess this function should be called `lauchMapper`, because that's what it does. It doesn't reduce multiple element into a single one, isn't it?

Just highlighting this because it is a bit confusing

Öffne final/server/src/datasources/launch.js bei der Definition von launchReducer und prüfe, wo sie an Array.map übergeben wird. Überprüfe alle weiteren Referenzen auf die Funktion und aktualisiere anschließend die Benennung konsistent, sodass der Name der Funktion ihre Mapping-Rolle widerspiegelt.

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