private static Parser buildFallbackParser(TikaConfig config) {
        Parser fallback = null;
        Parser p = config.getParser();
        if (p instanceof DefaultParser) {
            fallback = ((DefaultParser)p).getFallback();
        } else {
            fallback = new EmptyParser();
        }

        if (config.getAutoDetectParserConfig().getDigesterFactory() == null) {
            return fallback;
        } else {
            return new DigestingParser(fallback,
                    config.getAutoDetectParserConfig().getDigesterFactory().build(),
                    config.getAutoDetectParserConfig().getDigesterFactory().isSkipContainerDocument());
        }

    }
Creates an auto-detecting parser instance using the specified set of parser.
This allows one to create a Tika configuration where only a subset of the
available parsers have their 3rd party jars included, as otherwise the
use of the default TikaConfig will throw various "ClassNotFound" exceptions.

@param parsers
tika-core/src/main/java/org/apache/tika/parser/AutoDetectParser.java