ExtractReader.ALTER_METADATA_LIST getAlterMetadata(Map<String, String> localAttrs) {

        String alterExtractString = localAttrs.get("alterExtract");
        ExtractReader.ALTER_METADATA_LIST alterExtractList;
        if (alterExtractString == null || alterExtractString.equalsIgnoreCase("as_is")) {
            alterExtractList = ExtractReader.ALTER_METADATA_LIST.AS_IS;
        } else if (alterExtractString.equalsIgnoreCase("first_only")) {
            alterExtractList = ExtractReader.ALTER_METADATA_LIST.FIRST_ONLY;
        } else if (alterExtractString.equalsIgnoreCase("concatenate_content")) {
            alterExtractList = ExtractReader.ALTER_METADATA_LIST.CONCATENATE_CONTENT_INTO_FIRST;
        } else {
            throw new RuntimeException("options for alterExtract: as_is, first_only, concatenate_content." + " I don't understand:" + alterExtractString);
        }
        return alterExtractList;
    }
@return the main tables, not including the ref tables
tika-eval/tika-eval-app/src/main/java/org/apache/tika/eval/app/batch/EvalConsumerBuilder.java