exports.handler = (event, context, callback) => {
  https.get(url, (res) => {
    callback(null, res.statusCode)
  }).on('error', (e) => {
    callback(Error(e))
  })
}

exports.handler = async (event) => { 
  return new Promise((resolve, reject) => {
    if (Math.random() * 2 ^ 0) {
      resolve();
    } else {
      reject();
    }
  });
}

exports.handler = async (event) => {
  return https.get(url).promise();
}

var lambda = new AWS.Lambda();
lambda.addLayerVersionPermission(params, function (err, data) {
  if (err) console.log(err, err.stack); // an error occurred
  else     console.log(data);           // successful response
});

var lambda = new AWS.Lambda();
lambda.addLayerVersionPermission(params).promise();