private void init() {
        if (builder == null) {
            builder = new TinyBuilder(pipe);

            receivingContentHandler.reset();
            receivingContentHandler.setPipelineConfiguration(pipe);
            receivingContentHandler.setReceiver(builder);

            handler = receivingContentHandler;
        }
    }
Stops buffering SAX events and clears the buffer.
stroom-pipeline/src/main/java/stroom/pipeline/filter/TinyTreeBufferFilter.java