@Override
    public void processingInstruction(final String target, final String data) throws SAXException {
        handler.processingInstruction(target, data);
        super.processingInstruction(target, data);
    }
@param target the processing instruction target
@param data   the processing instruction data, or null if none was supplied.
              The data does not include any whitespace separating it from
              the target
@throws SAXException any SAX exception, possibly wrapping another exception
@see AbstractXMLFilter#processingInstruction(String,
String)
stroom-pipeline/src/main/java/stroom/pipeline/filter/AbstractSamplingFilter.java