presto-hive/src/main/java/io/prestosql/plugin/hive/util/HiveUtil.java/HiveUtil/getPrefilledColumnValue
class HiveUtil:    public static String getPrefilledColumnValue(HiveColumnHandle columnHandle, HivePartitionKey partitionKey, Path path, OptionalInt bucketNumber, long fileSize, long fileModifiedTime)
    {
        if (partitionKey != null) {
            return partitionKey.getValue();
        }
        if (isPathColumnHandle(columnHandle)) {
            return path.toString();
        }
        if (isBucketColumnHandle(columnHandle)) {
            return String.valueOf(bucketNumber.getAsInt());
        }
        if (isFileSizeColumnHandle(columnHandle)) {
            return String.valueOf(fileSize);
        }
        if (isFileModifiedTimeColumnHandle(columnHandle)) {
            return String.valueOf(fileModifiedTime);
        }
        throw new PrestoException(NOT_SUPPORTED, "unsupported hidden column: " + columnHandle);
    }