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lib/cartodb/controllers/layergroup/tile.js

@@ -41,7 +41,9 @@ module.exports = class TileLayergroupController {
     }
 
     register (mapRouter) {
+        // REGEXP matches with positive and negative numnbers
         const number = () => `(-?\\d+)`;
+        // REGEXP doesn't match with `val`
         const not = (val) => `(?!${val})([^\/]+?)`;
 
         mapRouter.get(