public ClickHouseColumn getValueInfo() {
        return dataType == ClickHouseDataType.Map && nested.size() == 2 ? nested.get(1) : null;
    }
Sets zero-based column index and column count.

@param index zero-based column index, negative number is treated as zero
@param count column count, should be always greater than one
clickhouse-data/src/main/java/com/clickhouse/data/ClickHouseColumn.java