@Override
    public void startStream() {
        // Assume the first line is the XML declaration.
        lineNo = 1;
        colNo = 0;
        depth = 0;
        inStartElement = false;
        super.startStream();
    }
This method tells filters that a stream is about to be parsed so that
they can complete any setup necessary.
stroom-pipeline/src/main/java/stroom/pipeline/filter/ResultLocator.java