private boolean assignableFrom(
            Collection<Class<? extends EncodingDetector>> excludeEncodingDetectors,
            Class<? extends EncodingDetector> encodingDetector) {
        for (Class<? extends EncodingDetector> e : excludeEncodingDetectors) {
            if (e.isAssignableFrom(encodingDetector)) {
                return true;
            }
        }
        return false;
    }
@param input    text document input stream, or <code>null</code>
@param metadata input metadata for the document
@return the detected Charset or null if no charset could be detected
@throws IOException
tika-core/src/main/java/org/apache/tika/detect/CompositeEncodingDetector.java