private function readmeExamples() { PromisePay::AsyncClient(function () { PromisePay::Token()->generateCardToken('CARD_TOKEN_ID'); }, function () { PromisePay::Transaction()->get('TRANSACTION_ID'); }, function () { PromisePay::Transaction()->getUser('USER_ID'); }, function () { PromisePay::BatchTransactions()->listTransactions(); })->done($cardToken, $transaction, $transactionUser, $batchTransactions); }