title: CloudKit: multiple users writing to same record at same time
body: <p>I am currently working on handling CloudKit errors for an app I've been developing. One major issue I need to handle is this: multiple users writing to the same record at the same time. </p>
  
  <p>What is the best way to handle this issue with CloudKit (in Swift)? Do I need to add some sort of lock on the record so that only one user can edit at a time? Does CloudKit do this for me automatically? If so, should I re-try the operation after some interval of time? Do I need a queue to hold tasks that are waiting to be done on that record?</p>
  
  <p>Any insight into how CloudKit intends for me to handle these sorts of issues would be much appreciated! Thanks!</p>