create_new_transaction_with_client_and_payment.java

TransactionService transactionService = paymillContext.getTransactionService();
Transaction transaction = transactionService.createWithPaymentAndClient(
    "pay_a818b847db6ce5ff636f",
    "client_c781b1d2f7f0f664b4d9",
    4200,
    "EUR"
);