fn prepare_signer_addition(
env: soroban_sdk::Env,
account: soroban_sdk::Address,
new_signer: soroban_sdk::Address,
current_min_weight: u32,
) -> SignerOperation
fn get_prepared_operation(
env: soroban_sdk::Env,
account: soroban_sdk::Address,
) -> Option
fn mark_executed(env: soroban_sdk::Env, account: soroban_sdk::Address)