One of the primary features of Gallery is enabling users to display their NFTs. To facilitate this, we need a quick way to retrieve all NFTs that belong to any given wallet address. Unfortunately, the Ethereum blockchain was not designed with a magical "get me every token that person owns" command, let alone other ways to slice the data: handling NFTs that are staked or escrowed, retrieving NFTs that were created by a specific address, retrieving NFTs an address once owned in the past, etc.