code: function(layer, b) {
      // shift arguments to maintain caompatibility
      if(b == undefined) {
        b = layer;
        layer = 0;
      }
      var layerInteraction;
      this.interactionEnabled[layer] = b;
      if(!b) {
        layerInteraction = this.interaction[layer];
        if(layerInteraction) {
          layerInteraction.remove();
          this.interaction[layer] = null;
        }
      } else {
        // if urls is null it means that setInteraction will be called
        // when the layergroup token was recieved, then the real interaction
        // layer will be created
        if(this.urls) {
          // generate the tilejson from the urls. wax needs it
          var layer_index = this.getLayerIndexByNumber(+layer);
          var tilejson = this._tileJSONfromTiles(layer_index, this.urls);
  
          // remove previous
          layerInteraction = this.interaction[layer];
          if(layerInteraction) {
            layerInteraction.remove();
          }
          var self = this;
  
          // add the new one
          this.interaction[layer] = this.interactionClass()
            .map(this.options.map)
            .tilejson(tilejson)
            .on('on', function(o) {
              if (self._interactionDisabled) return;
              o.layer = +layer;
              self._manageOnEvents(self.options.map, o);
            })
            .on('off', function(o) {
              if (self._interactionDisabled) return;
              o = o || {}
              o.layer = +layer;
              self._manageOffEvents(self.options.map, o);
            });
        }
      }
      return this;
    }
docs: Active or desactive interaction
  @params enable {Number} layer number
  @params layer {Boolean} Choose if wants interaction or not