docs: Quick Javadoc fixes.

src/main/java/io/reactivex/rxjava3/internal/fuseable/FuseToFlowable.java

@@ -21,8 +21,10 @@
  * the operator goes from Flowable to some other reactive type and then the sequence calls
  * for toFlowable again:
  * <pre>
- * Single&lt;Integer> single = Flowable.range(1, 10).reduce((a, b) -> a + b);
- * Flowable&lt;Integer> flowable = single.toFlowable();
+ * {@code 
+ * Single<Integer> single = Flowable.range(1, 10).reduce((a, b) -> a + b);
+ * Flowable<Integer> flowable = single.toFlowable();
+ * }
  * </pre>
  *
  * The {@code Single.toFlowable()} will check for this interface and call the {@link #fuseToFlowable()}

src/main/java/io/reactivex/rxjava3/internal/fuseable/FuseToMaybe.java

@@ -21,8 +21,10 @@
  * the operator goes from Maybe to some other reactive type and then the sequence calls
  * for toMaybe again:
  * <pre>
- * Single&lt;Integer> single = Maybe.just(1).isEmpty();
- * Maybe&lt;Integer> maybe = single.toMaybe();
+ * {@code 
+ * Single<Integer> single = Maybe.just(1).isEmpty();
+ * Maybe<Integer> maybe = single.toMaybe();
+ * }
  * </pre>
  *
  * The {@code Single.toMaybe()} will check for this interface and call the {@link #fuseToMaybe()}

src/main/java/io/reactivex/rxjava3/internal/fuseable/FuseToObservable.java

@@ -21,8 +21,10 @@
  * the operator goes from Observable to some other reactive type and then the sequence calls
  * for toObservable again:
  * <pre>
- * Single&lt;Integer> single = Observable.range(1, 10).reduce((a, b) -> a + b);
- * Observable&lt;Integer> observable = single.toObservable();
+ * {@code
+ * Single<Integer> single = Observable.range(1, 10).reduce((a, b) -> a + b);
+ * Observable<Integer> observable = single.toObservable();
+ * }
  * </pre>
  *
  * The {@code Single.toObservable()} will check for this interface and call the {@link #fuseToObservable()}

src/main/java/io/reactivex/rxjava3/internal/schedulers/SchedulerWhen.java

@@ -53,11 +53,13 @@
  * thread pool:
  *
  * <pre>
+ * {@code 
  * Scheduler limitScheduler = Schedulers.computation().when(workers -> {
  *  // use merge max concurrent to limit the number of concurrent
  *  // callbacks two at a time
  *  return Completable.merge(Observable.merge(workers), 2);
  * });
+ * }
  * </pre>
  * <p>
  * This is a slightly different way to limit the concurrency but it has some
@@ -71,11 +73,13 @@
  * to the second.
  *
  * <pre>
+ * {@code 
  * Scheduler limitScheduler = Schedulers.computation().when(workers -> {
  *  // use merge max concurrent to limit the number of concurrent
  *  // Observables two at a time
  *  return Completable.merge(Observable.merge(workers, 2));
  * });
+ * }
  * </pre>
  *
  * Slowing down the rate to no more than than 1 a second. This suffers from the
@@ -84,13 +88,15 @@
  * algorithm).
  *
  * <pre>
+ * {@code 
  * Scheduler slowScheduler = Schedulers.computation().when(workers -> {
  *  // use concatenate to make each worker happen one at a time.
  *  return Completable.concat(workers.map(actions -> {
  *      // delay the starting of the next worker by 1 second.
  *      return Completable.merge(actions.delaySubscription(1, TimeUnit.SECONDS));
  *  }));
  * });
+ * }
  * </pre>
  * <p>History 2.0.1 - experimental
  * @since 2.1

src/test/java/io/reactivex/rxjava3/internal/operators/flowable/BlockingFlowableNextTest.java

@@ -223,8 +223,8 @@ public void nextWithCallingHasNextMultipleTimes() {
 
     /**
      * Confirm that no buffering or blocking of the Observable onNext calls occurs and it just grabs the next emitted value.
-     * <p/>
-     * This results in output such as => a: 1 b: 2 c: 89
+     * <p>
+     * This results in output such as {@code => a: 1 b: 2 c: 89}
      *
      * @throws Throwable some method call is declared throws
      */

src/test/java/io/reactivex/rxjava3/internal/operators/observable/BlockingObservableNextTest.java

@@ -227,8 +227,8 @@ public void nextWithCallingHasNextMultipleTimes() {
 
     /**
      * Confirm that no buffering or blocking of the Observable onNext calls occurs and it just grabs the next emitted value.
-     * <p/>
-     * This results in output such as => a: 1 b: 2 c: 89
+     * <p>
+     * This results in output such as {@code => a: 1 b: 2 c: 89}
      *
      * @throws Throwable some method call is declared throws
      */

src/test/java/io/reactivex/rxjava3/observers/SerializedObserverTest.java

@@ -340,11 +340,11 @@ public void onNext(String t) {
      *
      * When using SynchronizedSubscriber we get this output:
      *
-     * p1: 18 p2: 68 => should be close to each other unless we have thread starvation
+     * {@code p1: 18 p2: 68 =>} should be close to each other unless we have thread starvation
      *
      * When using SerializedObserver we get:
      *
-     * p1: 1 p2: 2445261 => should be close to each other unless we have thread starvation
+     * {@code p1: 1 p2: 2445261 =>} should be close to each other unless we have thread starvation
      *
      * This demonstrates how SynchronizedSubscriber balances back and forth better, and blocks emission.
      * The real issue in this example is the async buffer-bloat, so we need backpressure.
@@ -1042,8 +1042,7 @@ public void run() {
                 }
             };
 
-            TestHelper.race(r1, r2);
-
+            TestHelper.race(r1, r2);       
             to.awaitDone(5, TimeUnit.SECONDS)
             .assertError(ex)
             .assertNotComplete();

src/test/java/io/reactivex/rxjava3/subscribers/SerializedSubscriberTest.java

@@ -341,11 +341,11 @@ public void onNext(String t) {
      *
      * When using SynchronizedSubscriber we get this output:
      *
-     * p1: 18 p2: 68 => should be close to each other unless we have thread starvation
+     * {@code p1: 18 p2: 68 =>} should be close to each other unless we have thread starvation
      *
      * When using SerializedSubscriber we get:
      *
-     * p1: 1 p2: 2445261 => should be close to each other unless we have thread starvation
+     * {@code p1: 1 p2: 2445261 =>} should be close to each other unless we have thread starvation
      *
      * This demonstrates how SynchronizedSubscriber balances back and forth better, and blocks emission.
      * The real issue in this example is the async buffer-bloat, so we need backpressure.

src/test/java/io/reactivex/rxjava3/tck/BaseTck.java

@@ -51,7 +51,7 @@ public long maxElementsFromPublisher() {
 
     /**
      * Creates an Iterable with the specified number of elements or an infinite one if
-     * elements > {@link Integer#MAX_VALUE}.
+     * {@code elements >} {@link Integer#MAX_VALUE}.
      * @param elements the number of elements to return, {@link Integer#MAX_VALUE} means an infinite sequence
      * @return the Iterable
      */