Remove redundant comments.

Author: vbabanin

driver-core/src/main/com/mongodb/internal/async/AsyncTrampoline.java

@@ -46,8 +46,7 @@ public final class AsyncTrampoline {
 
     private static final ThreadLocal<Bounce> TRAMPOLINE = new ThreadLocal<>();
 
-    private AsyncTrampoline() {
-    }
+    private AsyncTrampoline() {}
 
     /**
      * Execute work through the trampoline. If no trampoline is active, become the owner
@@ -56,15 +55,12 @@ private AsyncTrampoline() {
     public static void run(final Runnable work) {
         Bounce bounce = TRAMPOLINE.get();
         if (bounce != null) {
-            // Re-entrant, enqueue and return
             bounce.enqueue(work);
         } else {
-            // Become the trampoline owner.
             bounce = new Bounce();
             TRAMPOLINE.set(bounce);
             try {
                 work.run();
-                // drain any re-entrant work iteratively
                 while (bounce.work != null) {
                     Runnable workToRun = bounce.work;
                     bounce.work = null;
@@ -87,8 +83,7 @@ private static final class Bounce {
 
         void enqueue(final Runnable task) {
             if (this.work != null) {
-                throw new AssertionError("Trampoline slot already occupied. "
-                        + "It could happen if there are multiple concurrent operations in a sequential async chain.");
+                throw new AssertionError("Trampoline slot already occupied");
             }
             this.work = task;
         }

driver-core/src/main/com/mongodb/internal/async/function/AsyncCallbackLoop.java

@@ -59,19 +59,15 @@ public void run(final SingleResultCallback<Void> callback) {
 
     /**
      * This callback is allowed to be completed more than once.
-     * Also implements {@linkplain Runnable} to avoid lambda allocation per iteration when using trampoline.
      */
     @NotThreadSafe
-    private class LoopingCallback implements SingleResultCallback<Void>, Runnable {
+    private class LoopingCallback implements SingleResultCallback<Void> {
         private final SingleResultCallback<Void> wrapped;
+        private final Runnable nextIteration;
 
         LoopingCallback(final SingleResultCallback<Void> callback) {
             wrapped = callback;
-        }
-
-        @Override
-        public void run() {
-            body.run(this);
+            nextIteration = () -> body.run(this);
         }
 
         @Override
@@ -87,7 +83,7 @@ public void onResult(@Nullable final Void result, @Nullable final Throwable t) {
                     return;
                 }
                 if (continueLooping) {
-                    AsyncTrampoline.run(this);
+                    AsyncTrampoline.run(nextIteration);
                 } else {
                     wrapped.onResult(result, null);
                 }