code: private void doLastValue(HttpServletResponse httpResponse, String graphName)
  			throws IOException {
  		httpResponse.setContentType("text/plain");
  		boolean first = true;
  		for (final String graph : graphName.split(",")) {
  			final JRobin jrobin = collector.getJRobin(graph);
  			final double lastValue;
  			if (jrobin == null) {
  				lastValue = -1;
  			} else {
  				lastValue = jrobin.getLastValue();
  			}
  			if (first) {
  				first = false;
  			} else {
  				httpResponse.getWriter().write(",");
  			}
  			httpResponse.getWriter().write(String.valueOf(lastValue));
  		}
  		httpResponse.flushBuffer();
  	}
docs: part=lastValue&graph=x,y,z sera utilisé par munin notamment