public void appendStringFormVals(List<String> vals) {
            for (String val : vals) {
                if (curColIndex >= columnTypes.length) {
                    return;
                }
                appendStringFormVal(val);
            }
        }
A simple row can only store simple values like int, double, string. But cannot store multi-value column.
indexr-segment/src/main/java/io/indexr/segment/helper/SimpleRow.java