default Mutation write() {
        return getRequest().write();
    }
Sets mirrored output stream, which will be later used for dumping all
{@link java.sql.ResultSet} generated by this statement, via
{@link com.clickhouse.data.ClickHouseInputStream#setCopyToTarget(OutputStream)}.

@param out mirrored output stream, could be null
clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/ClickHouseStatement.java