docs: public static <K, V> Map<K, V> eachWithIndex(Map<K, V> self, @ClosureParams(value=MapEntryOrKeyValue.class, options="index=true") Closure closure) {
          int counter = 0;
          for (Map.Entry entry : self.entrySet()) {
              callClosureForMapEntryAndCounter(closure, entry, counter++);
          }
          return self;
      }