def set_display_name(user_id, prefix, suffix):
# get the current name
old_display_name = get_EnkiUserDisplayName_by_user_id_current(user_id)
# save the new name
display_name = EnkiModelDisplayName(parent=ndb.Key(EnkiModelUser, user_id),
user_id=user_id,
prefix=prefix,
suffix=suffix)
display_name.put()
if old_display_name:
# if the user already had a display name, and a new same was set, set the old name to not current
old_display_name.current = False
old_display_name.put()
