Create StringMap

utils.js

@@ -24,3 +24,21 @@ function intersects(set1, set2) {
   }
   return false;
 }
+
+class StringMap extends Map {
+  has(key) {
+    return super.has(key.toString());
+  }
+
+  get(key) {
+    return super.get(key.toString());
+  }
+
+  set(key, value) {
+    return super.set(key.toString(), value);
+  }
+
+  delete(key) {
+    return super.delete(key.toString());
+  }
+}