@Override
        public void visit(TraceNode node) {
            if ( ! (node.payload() instanceof String)) return; // skip other info than trace messages
            try {
                jsonWriter.beginArrayValue();
                if (node.timestamp() != 0) { // render object
                    jsonWriter.beginObject();
                    jsonWriter.beginField("timestamp").value(node.timestamp()).endField();
                    jsonWriter.beginField("message").value(node.payload().toString()).endField();
                    jsonWriter.endObject();
                }
                else { // render string
                    jsonWriter.value(node.payload().toString());
                }
                jsonWriter.endArrayValue();
            }
            catch (IOException e) {
                throw new WrappedIOException(e);
            }
        }
Returns whether this data element should be rendered.
This can be overridden to add new kinds of data which should not be rendered.
This default implementation returns true unless the data is instanceof ResponseHeaders.

@return true to render it, false to skip completely
container-core/src/main/java/com/yahoo/processing/rendering/ProcessingRenderer.java