Hello,

I am implementing a web service that will use the Zoho API through the Java SDK.

I see that `ZohoOAuthDBPersistence`  allows to store multiple authentication informations. So let's imagine I have two records in the database: two users, each one with a refresh token.

Now l want to upload a file, I see the example code:

1. ZCRMRecord record = ZCRMRecord.getInstance("Leads",35240330409001L);
   
2. APIResponse responseIn = record.uploadAttachment("path/to/file");
   

How can I choose which user's access token will be used ?

Will there be race conditions with the use of asynchronous code ?