public void setMetadataExtractionPatterns(Map<Pattern, String> patterns) {
        this.metadataPatterns = patterns;
    }
Sets the map of regular expression patterns and Metadata
keys. Any matching patterns will have the matching
metadata entries set.
Set this to null to disable Metadata extraction.
tika-core/src/main/java/org/apache/tika/parser/external/ExternalParser.java