code: def populate_user(self):
          
          user = None
  
          try:
              # self.attrs will only be non-None if we were able to load this user
              # from the LDAP directory, so this filters out nonexistent users.
              if self.attrs is not None:
                  self._get_or_create_user(force_populate=True)
  
              user = self._user
          except ldap.LDAPError as e:
              results = ldap_error.send(self.backend.__class__,
                                        context='populate_user', exception=e)
              if len(results) == 0:
                  logger.warning(u"Caught LDAPError while authenticating %s: %s",
                                 self._username, pprint.pformat(e))
          except Exception as e:
              logger.error(u"Caught Exception while authenticating %s: %s",
                           self._username, pprint.pformat(e))
              logger.error(''.join(traceback.format_tb(sys.exc_info()[2])))
              raise
  
          return user
docs: Populates the Django user object using the default bind credentials.