One of our clients has a requirement to migrate attachments to Salesforce Files. Salesforce Files (ContentDocument) object doesn't support insert().
They have also enabled this option from Winter '16 to allow file uploads to goto salesforce files instead of attachments.


I have confirmed from Salesforce docs and data loader pertaining ContentDocument's supported calls. Now, is there a way I can still pull this task off of migrating attachments to salesforce files?