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",
                  user=self._user,
                  exception=e,
              )
              if len(results) == 0:
                  logger.warning(
                      "Caught LDAPError while authenticating {}: {}".format(
                          self._username, pprint.pformat(e)
                      )
                  )
          except Exception as e:
              logger.warning("{} while authenticating {}".format(e, self._username))
              raise
  
          return user
docs: Populates the Django user object using the default bind credentials.