can somebody explain what does force_chain function does in smart contract? i can not find it's definition in docs

it ensures that execution will continue only if the address it accepts as an argument doesn't reside in the masterchain

Its not a standard function, thats why its not in docs

dankon!

where does this function comes from then?

you should find it in source codes of the contract, like utils.fc or file like it

which contract are you reviewing?

this smart contract. but i can't fing this function
https://tonviewer.com/EQB32bnYd8yl57TPQqG4OF7rNtAAoZz_jemQRveLO0Z4TVf0?section=Source+code

oh. i'm just blind. i found it.....

https://github.com/ton-blockchain/token-contract/blob/main/nft/params.fc#L3

sorry