Remove unnecessary comments

Author: GWphua

processing/src/main/java/org/apache/druid/query/groupby/GroupByQueryQueryToolChest.java

@@ -209,8 +209,6 @@ private Sequence<ResultRow> initAndMergeGroupByResults(
 
   private void populateQueryMetrics(GroupByQueryMetrics queryMetrics, ResponseContext context)
   {
-    // TODO: Everything is working as expected now, but the GroupByQueryMetrics expects to emit the metrics directly.
-    //  Why not we also send the values individually to the GroupByStatsMonitor?
     Object bytesSpilledToStorage = context.get(GroupByResponseContextKeys.GROUPBY_BYTES_SPILLED_TO_STORAGE_KEY);
 
     if (bytesSpilledToStorage != null) {

processing/src/main/java/org/apache/druid/query/groupby/epinephelinae/ConcurrentGrouper.java

@@ -414,22 +414,20 @@ private List<CloseableIterator<Entry<KeyType>>> parallelSortAndGetGroupersIterat
   {
     // The number of groupers is same with the number of processing threads in the executor
     final List<ListenableFuture<CloseableIterator<Entry<KeyType>>>> futures = groupers.stream()
-                                                                                      .map(grouper ->
-                                                                                               executor.submit(
-                                                                                                   new AbstractPrioritizedCallable<CloseableIterator<Entry<KeyType>>>(
-                                                                                                       priority)
-                                                                                                   {
-                                                                                                     @Override
-                                                                                                     public CloseableIterator<Entry<KeyType>> call()
-                                                                                                     {
-                                                                                                       return grouper.iterator(
-                                                                                                           true);
-                                                                                                     }
-                                                                                                   }
-                                                                                               )
-                                                                                      )
-                                                                                      .collect(Collectors.toList()
-                                                                                      );
+                .map(grouper ->
+                         executor.submit(
+                             new AbstractPrioritizedCallable<CloseableIterator<Entry<KeyType>>>(priority)
+                             {
+                               @Override
+                               public CloseableIterator<Entry<KeyType>> call()
+                               {
+                                 return grouper.iterator(true);
+                               }
+                             }
+                         )
+                )
+                .collect(Collectors.toList()
+    );
 
     ListenableFuture<List<CloseableIterator<Entry<KeyType>>>> future = Futures.allAsList(futures);
     try {

processing/src/main/java/org/apache/druid/query/groupby/epinephelinae/GroupByMergingQueryRunner.java

@@ -146,7 +146,6 @@ public Sequence<ResultRow> run(final QueryPlus<ResultRow> queryPlus, final Respo
         CTX_KEY_MERGE_RUNNERS_USING_CHAINED_EXECUTION,
         false
     );
-
     final QueryPlus<ResultRow> queryPlusForRunners = queryPlus
         .withQuery(
             query.withOverriddenContext(ImmutableMap.of(CTX_KEY_MERGE_RUNNERS_USING_CHAINED_EXECUTION, true))