Set this remove to be safe.  It will call getLastError after the
            remove to make sure it was successful.  ``**kwargs`` are parameters to
            MongoDB's getLastError command (as in pymongo's remove).

def set_safe(self, is_safe, **kwargs):
        ''' Set this remove to be safe.  It will call getLastError after the
            remove to make sure it was successful.  ``**kwargs`` are parameters to
            MongoDB's getLastError command (as in pymongo's remove).
        '''
        self.safe = is_safe
        self.get_last_args.update(**kwargs)
        return self