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kotlinlang

Hello!

Android library Picasso has a `fetch(Callback)` method which asynchronously delivers results of fetching. It is used for warming up image cache for a certain file. But I need to warm up 10 image files sequentially and wrap it up ideally in some sort of `Completable` (or other Rx element).

How would you approach this?

<https://square.github.io/picasso/2.x/picasso/com/squareup/picasso/RequestCreator.html#fetch-com.squareup.picasso.Callback->