Error bars on the plot?

I have a simple question. I love the "Spark line appender" block, but it would be great to have something like this with error bars option. Is there an easy way to write such functionality?

Thank you - 

Dmitry.

All sources are available through our update site and can directly be used within the KNIME SDK which is an Eclipse-based KNIME IDE so to speak. The spark lines node is contained within the org.knime.ext.svg.node.sparklines package.