presto-jdbc/src/main/java/io/prestosql/jdbc/PrestoStatement.java/PrestoStatement/cancel
class PrestoStatement:    @Override
    public void cancel()
            throws SQLException
    {
        checkOpen();

        StatementClient client = executingClient.get();
        if (client != null) {
            client.close();
        }

        closeResultSet();
    }