vendor/ember-leaflet-cartodb/cartodb_noleaflet.js
function(number) {
    var layers = {}
    var c = 0;
    for(var i = 0; i < this.layers.length; ++i) {
      var layer = this.layers[i];
      layers[i] = c;
      if(layer.options && !layer.options.hidden) {
        ++c;
      }
    }
    return layers[number];
  }
function(number) {
    var layers = {}
    var c = 0;
    for(var i = 0; i < this.layers.length; ++i) {
      var layer = this.layers[i];
      layers[i] = c;
      if(layer.options && !layer.options.hidden) {
        ++c;
      }
    }
    return layers[number];
  }
function ( number ) { var layers = { } var c = 0 ; for ( var i = 0 ; i < this . layers . length ; ++ i ) { var layer = this . layers [ i ] ; layers [ i ] = c ; if ( layer . options && ! layer . options . hidden ) { ++ c ; } } return layers [ number ] ; }
given number inside layergroup returns the real index in tiler layergroup`
given number inside layergroup returns the real index in tiler layergroup