presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/backup/HttpBackupStore.java/HttpBackupStore/shardExists
class HttpBackupStore:    @Override
    public boolean shardExists(UUID uuid)
    {
        Request request = prepareHead()
                .addHeader(PRESTO_ENVIRONMENT, environment)
                .setUri(shardUri(uuid))
                .build();

        try {
            StatusResponse status = httpClient.execute(request, createStatusResponseHandler());
            if (isOk(status)) {
                return true;
            }
            if (isNotFound(status) || isGone(status)) {
                return false;
            }
            throw badResponse(status);
        }
        catch (RuntimeException e) {
            throw new PrestoException(RAPTOR_BACKUP_ERROR, "Failed to check if shard exists: " + uuid, e);
        }
    }