:param account: a zobjects.Account
        :param attrs  : a dictionary of attributes to set ({key:value,...})

def modify_account(self, account, attrs):
        """
        :param account: a zobjects.Account
        :param attrs  : a dictionary of attributes to set ({key:value,...})
        """
        attrs = [{'n': k, '_content': v} for k, v in attrs.items()]
        self.request('ModifyAccount', {
            'id': self._get_or_fetch_id(account, self.get_account),
            'a': attrs
        })