fn get_escrow(env: soroban_sdk::Env, tx_id: u64) -> EscrowState
fn get_status(env: soroban_sdk::Env, tx_id: u64) -> EscrowStatus
fn refund_buyer(env: soroban_sdk::Env, tx_id: u64, caller: soroban_sdk::Address)
fn create_escrow(
env: soroban_sdk::Env,
buyer: soroban_sdk::Address,
seller: soroban_sdk::Address,
token: soroban_sdk::Address,
amount: i128,
) -> u64
fn confirm_delivery(env: soroban_sdk::Env, tx_id: u64, buyer: soroban_sdk::Address)