title: How to Customize ObjectId in Parse from swift while creating an object
body: <p>I have three classes for my app in Parse. Say A, B, C. </p>
  
  <p>Whenever I create an object in A class, the object id should start with A and have 15 digits.</p>
  
  <p>Likewise whenever I create an object in B class, the object id should start with B and have 11 digits.</p>
  
  <p>I also want to ensure that the object id is not repeating. </p>
  
  <p>Can I do them by any way?</p>