private static MediaType detectOverrides(Metadata metadata) {
        String override = metadata.get(TikaCoreProperties.CONTENT_TYPE_USER_OVERRIDE);
        if (!StringUtils.isBlank(override)) {
            MediaType mt = MediaType.parse(override);
            if (mt != null) {
                return mt;
            }
        }
        override = metadata.get(TikaCoreProperties.CONTENT_TYPE_PARSER_OVERRIDE);
        if (!StringUtils.isBlank(override)) {
            MediaType mt = MediaType.parse(override);
            if (mt != null) {
                return mt;
            }
        }
        return null;
    }
@param metadata
@return mediaType if a parseable mediatype was sent in via user or parser overrides
tika-core/src/main/java/org/apache/tika/detect/CompositeDetector.java