fn initialize(env: soroban_sdk::Env, admin: soroban_sdk::Address, total_supply: i128)
fn balance(env: soroban_sdk::Env, owner: soroban_sdk::Address) -> i128
fn transfer(
env: soroban_sdk::Env,
from: soroban_sdk::Address,
to: soroban_sdk::Address,
amount: i128,
) -> bool
fn total_supply(env: soroban_sdk::Env) -> i128