public void setEncodingDetector(EncodingDetector encodingDetector) {
        this.encodingDetector = encodingDetector;
    }
Look for an EncodingDetetor in the ParseContext.  If it hasn't been
passed in, use the original EncodingDetector from initialization.

@param parseContext
@return
tika-core/src/main/java/org/apache/tika/parser/AbstractEncodingDetectorParser.java