protected void resetPermissions(DocumentModel doc, String userName) {
   ACP acp = session.getACP(doc.getRef());
   ACL localACL = acp.getOrCreateACL(ACL.LOCAL_ACL);
   Iterator<ACE> localACLIt = localACL.iterator();
   while (localACLIt.hasNext()) {
     ACE ace = localACLIt.next();
     if (userName.equals(ace.getUsername())) {
       localACLIt.remove();
     }
   }
   session.setACP(doc.getRef(), acp, true);
   session.save();
 }
 protected void resetPermissions(DocumentRef docRef, String userName) {
   ACP acp = session.getACP(docRef);
   ACL localACL = acp.getOrCreateACL(ACL.LOCAL_ACL);
   Iterator<ACE> localACLIt = localACL.iterator();
   while (localACLIt.hasNext()) {
     ACE ace = localACLIt.next();
     if (userName.equals(ace.getUsername())) {
       localACLIt.remove();
     }
   }
   session.setACP(docRef, acp, true);
   TransactionHelper.commitOrRollbackTransaction();
   TransactionHelper.startTransaction();
 }