   chart.useLog10BandSplitting = (_) -> if (!arguments.length) then useLog10Bands else useLog10Bands = _; chart
   chart.showLegend = (_) -> if (!arguments.length) then showLegend else showLegend = _; chart
 
-  # Supported events: "applyFilter", ""
+  # Supported events: "applyFilter", "ruleMoved"
   chart.on = (eventName, listener) -> 
     (eventListeners[eventName] ?= []).push(listener); chart
 

    if listeners?
      l.apply(chart, args) for l in listeners


  colorsBetween = (start, end, numColors) ->
    scale = d3.scale.linear()

    .concat colorsBetween("#e5f5e0",d3.hcl("#00441b").darker(), numBands)  # positive


  parent = null
  width = bandWidth
  height = bandHeight
  tscale = d3.time.scale().range([0, width])
