CharsetMatch match(CharsetDetector det) {
            int confidence = match(det, commonChars);
            return confidence == 0 ? null : new CharsetMatch(det, this, confidence);
        }
GB-18030 recognizer. Uses simplified Chinese statistics.
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-text-module/src/main/java/org/apache/tika/parser/txt/CharsetRecog_mbcs.java