private HeatMapColumn buildMissingColumn(String id, int defaultValue) {
        HeatMapColumn column = new HeatMapColumn();
        column.setId(id);
        buckets.forEach(bucket -> {
            column.addValue((long) defaultValue);
        });
        return column;
    }
Build one heatmap value column based on rawdata in the storage and row id.

@param id      of the row
@param rawdata literal string, represent a {@link DataTable}
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/type/HeatMap.java