@Override
    public void release(final ConnectionSession connectionSession) {
        MySQLStatementIdGenerator.getInstance().unregisterConnection(connectionSession.getConnectionId());
    }
@Test
    void assertRelease() {
        ConnectionSession connectionSession = mock(ConnectionSession.class);
        int connectionId = 1;
        when(connectionSession.getConnectionId()).thenReturn(connectionId);
        engine.release(connectionSession);
        verify(MySQLStatementIdGenerator.getInstance()).unregisterConnection(connectionId);
    }