From the Leaflet.OpacityControls plugin, you can add an opacity slider to a tiled layer by:
var opacitySlider = new L.Control.opacitySlider();
I want the opacity slide-bar to link to not just one layer, but the tiled raster layer with the largest z-index (i.e. upper most layer) at any given time. How should I replace the
interactive_layer var to do so?