protected void warn() {
        LOG.info("Tesseract is installed and is being invoked. " +
                "This can add greatly to processing time.  If you do not want tesseract " +
                "to be applied to your files see: " +
                "https://cwiki.apache.org/confluence/display/TIKA/TikaOCR#TikaOCR-disable-ocr");
        HAS_WARNED = true;
    }
Starts a thread that reads the contents of the standard output or error
stream of the given process to not block the process. The stream is closed
once fully processed.
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-ocr-module/src/main/java/org/apache/tika/parser/ocr/TesseractOCRParser.java