Is Arstotzka in Russia?

I'm curious, could you please clarify for me if the country of Arstotzka is located within the boundaries of Russia? It's a name that I've come across in a few contexts recently, but I'm having trouble pinpointing its exact geographical location. Is it a real country, or perhaps a fictional entity used in a particular story or game? I'd appreciate any information you could provide to help me better understand the origins and context of Arstotzka.