<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _get_groups(self):
 """ Returns an _LDAPUserGroups object, which can determine group membership. """

        if self._groups is None:
            self._groups = _LDAPUserGroups(self)

        return self._groups