private String readAnsiString(InputStream is) throws IOException {
        StringBuilder sb = new StringBuilder();
        int c = is.read();
        while (c > 0) {
            sb.append((char) c);
            c = is.read();
        }
        if (c == -1) {
            throw new IOException("Hit end of stream before end of AnsiString");
        }
        return sb.toString();
    }
can return null if there is a linked object
instead of an embedded file
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/rtf/RTFObjDataParser.java