https://medium.com/upday-devs/rxjava-subscribeon-vs-observeon-9af518ded53a
observeON -Acts downstream - thing that happen after the observeOn call - unlike subscribeOn
subscribeON - Influences the thread that is used when the Obserable is subscribed to and it will stay on it downstream. Position does not matter! If there are multiple instances of subscribeOn in the stream, only the first one has a pracical effect
