How to use the patroni.exceptions.PostgresConnectionException function in patroni

def test_query(self):
        self.p.query('select 1')
        self.assertRaises(PostgresConnectionException, self.p.query, 'RetryFailedError')
        self.assertRaises(psycopg2.ProgrammingError, self.p.query, 'blabla')

def test_update_lock(self):
        self.p.last_operation = Mock(side_effect=PostgresConnectionException(''))
        self.assertTrue(self.ha.update_lock(True))

def test__query(self):
        self.assertRaises(PostgresConnectionException, self.p._query, 'blabla')
        self.p._state = 'restarting'
        self.assertRaises(RetryFailedError, self.p._query, 'blabla')

def query(self, sql, *args, **kwargs):
        if not kwargs.get('retry', True):
            return self._query(sql, *args)
        try:
            return self.retry(self._query, sql, *args)
        except RetryFailedError as e:
            raise PostgresConnectionException(str(e))

def _cluster_info_state_get(self, name):
        if not self._cluster_info_state:
            try:
                result = self._is_leader_retry(self._query, self.cluster_info_query).fetchone()
                self._cluster_info_state = dict(zip(['timeline', 'wal_position', 'pg_control_timeline'], result))
            except RetryFailedError as e:  # SELECT failed two times
                self._cluster_info_state = {'error': str(e)}
                if not self.is_starting() and self.pg_isready() == STATE_REJECT:
                    self.set_state('starting')

        if 'error' in self._cluster_info_state:
            raise PostgresConnectionException(self._cluster_info_state['error'])

        return self._cluster_info_state.get(name)

cursor = self._connection.cursor()
            cursor.execute(sql, params)
            return cursor
        except psycopg2.Error as e:
            if cursor and cursor.connection.closed == 0:
                # When connected via unix socket, psycopg2 can't recoginze 'connection lost'
                # and leaves `_cursor_holder.connection.closed == 0`, but psycopg2.OperationalError
                # is still raised (what is correct). It doesn't make sense to continiue with existing
                # connection and we will close it, to avoid its reuse by the `cursor` method.
                if isinstance(e, psycopg2.OperationalError):
                    self._connection.close()
                else:
                    raise e
            if self.state == 'restarting':
                raise RetryFailedError('cluster is being restarted')
            raise PostgresConnectionException('connection problems')

cursor = self._cursor()
            cursor.execute(sql, params)
            return cursor
        except psycopg2.Error as e:
            if cursor and cursor.connection.closed == 0:
                # When connected via unix socket, psycopg2 can't recoginze 'connection lost'
                # and leaves `_cursor_holder.connection.closed == 0`, but psycopg2.OperationalError
                # is still raised (what is correct). It doesn't make sense to continiue with existing
                # connection and we will close it, to avoid its reuse by the `_cursor` method.
                if isinstance(e, psycopg2.OperationalError):
                    self.close_connection()
                else:
                    raise e
            if self.state == 'restarting':
                raise RetryFailedError('cluster is being restarted')
            raise PostgresConnectionException('connection problems')