How to delete the primarycontent of teh Document using api.

Following works with Windchill 10.2 M10

private boolean removePrimaryContent(final WTDocument wtDoc) {

boolean isSuccess = false;

ContentItem contentItem = null;

try {

contentItem = ContentHelper.service.getPrimary((FormatContentHolder)wtDoc);

if(contentItem != null){

System.out.println("deleting contentItem: " + contentItem.getDisplayIdentity());

PersistenceHelper.manager.delete(contentItem);

isSuccess = true;

}

} catch (WTException | PropertyVetoException e) {

isSuccess = false;

e.printStackTrace();

}

return isSuccess;

}