fn close(
env: soroban_sdk::Env,
from: soroban_sdk::Address,
id: u64,
) -> Result
fn open(
env: soroban_sdk::Env,
id: u64,
token: soroban_sdk::Address,
from: soroban_sdk::Address,
to: soroban_sdk::Address,
amount: i128,
) -> u64