正在尝试将Braintree嵌套回调转换为NodeJS async/await语法

const braintree = require('braintree');
const gateway = braintree.connect({
  environment: braintree.Environment.Sandbox,
  merchantId: 'your_merchant_id',
  publicKey: 'your_public_key',
  privateKey: 'your_private_key'
});

async function processPayment() {
  try {
    const clientToken = await gateway.clientToken.generate({});
    const result = await gateway.transaction.sale({
      amount: '10.00',
      paymentMethodNonce: 'nonce_from_the_client',
      options: {
        submitForSettlement: true
      }
    });

    if (result.success) {
      console.log('Payment successful!');
    } else {
      console.log('Payment failed:', result.message);
    }
  } catch (error) {
    console.error('Error occurred:', error);
  }
}

processPayment();