Question about Checkpoints #667
Description
Hello, I was reading BlockchairApiSyncer of BitcoinCore and i'm a little bit confused, Whats the point of Checkpoints and HsBlockHashFetcher? why blocks before checkpoint gets fetched from another api and the blocks after checkpoint gets fetched from blockchair api, Is it there just to save costs, Or it's for not trusting fully on blockchair? or is there another reason that i'm missing, Perhaps it needs comments to clarify it better. Thanks for the work.