3.x: Fix fromCompletionStage javadoc

src/main/java/io/reactivex/rxjava3/core/Completable.java

@@ -601,6 +601,7 @@ public static Completable fromCallable(@NonNull Callable<?> callable) {
      * @param future the {@code Future} to react to
      * @return the new {@code Completable} instance
      * @throws NullPointerException if {@code future} is {@code null}
+     * @see #fromCompletionStage(CompletionStage)
      */
     @CheckReturnValue
     @NonNull
@@ -3410,7 +3411,7 @@ public final TestObserver<Void> test(boolean dispose) {
      * <img width="640" height="262" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/fromCompletionStage.c.png" alt="">
      * <p>
      * Note that the operator takes an already instantiated, running or terminated {@code CompletionStage}.
-     * If the optional is to be created per consumer upon subscription, use {@link #defer(Supplier)}
+     * If the {@code CompletionStage} is to be created per consumer upon subscription, use {@link #defer(Supplier)}
      * around {@code fromCompletionStage}:
      * <pre><code>
      * Maybe.defer(() -&gt; Completable.fromCompletionStage(createCompletionStage()));

src/main/java/io/reactivex/rxjava3/core/Flowable.java

@@ -20033,7 +20033,7 @@ public final TestSubscriber<T> test(long initialRequest, boolean cancel) { // No
      * <img width="640" height="262" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/fromCompletionStage.f.png" alt="">
      * <p>
      * Note that the operator takes an already instantiated, running or terminated {@code CompletionStage}.
-     * If the optional is to be created per consumer upon subscription, use {@link #defer(Supplier)}
+     * If the {@code CompletionStage} is to be created per consumer upon subscription, use {@link #defer(Supplier)}
      * around {@code fromCompletionStage}:
      * <pre><code>
      * Flowable.defer(() -&gt; Flowable.fromCompletionStage(createCompletionStage()));

src/main/java/io/reactivex/rxjava3/core/Maybe.java

@@ -1109,6 +1109,7 @@ public abstract class Maybe<@NonNull T> implements MaybeSource<T> {
      * @return the new {@code Maybe} instance
      * @throws NullPointerException if {@code future} is {@code null}
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
+     * @see #fromCompletionStage(CompletionStage)
      */
     @CheckReturnValue
     @NonNull
@@ -1147,6 +1148,7 @@ public abstract class Maybe<@NonNull T> implements MaybeSource<T> {
      * @return the new {@code Maybe} instance
      * @throws NullPointerException if {@code future} or {@code unit} is {@code null}
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
+     * @see #fromCompletionStage(CompletionStage)
      */
     @CheckReturnValue
     @NonNull
@@ -6145,7 +6147,7 @@ public final TestObserver<T> test(boolean dispose) {
      * <img width="640" height="262" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/fromCompletionStage.s.png" alt="">
      * <p>
      * Note that the operator takes an already instantiated, running or terminated {@code CompletionStage}.
-     * If the optional is to be created per consumer upon subscription, use {@link #defer(Supplier)}
+     * If the {@code CompletionStage} is to be created per consumer upon subscription, use {@link #defer(Supplier)}
      * around {@code fromCompletionStage}:
      * <pre><code>
      * Maybe.defer(() -&gt; Maybe.fromCompletionStage(createCompletionStage()));

src/main/java/io/reactivex/rxjava3/core/Observable.java

@@ -2020,6 +2020,7 @@ public static int bufferSize() {
      * @return the new {@code Observable} instance
      * @throws NullPointerException if {@code future} is {@code null}
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
+     * @see #fromCompletionStage(CompletionStage)
      */
     @CheckReturnValue
     @NonNull
@@ -2062,6 +2063,7 @@ public static int bufferSize() {
      * @return the new {@code Observable} instance
      * @throws NullPointerException if {@code future} or {@code unit} is {@code null}
      * @see <a href="http://reactivex.io/documentation/operators/from.html">ReactiveX operators documentation: From</a>
+     * @see #fromCompletionStage(CompletionStage)
      */
     @CheckReturnValue
     @NonNull
@@ -16776,7 +16778,7 @@ public final TestObserver<T> test(boolean dispose) { // NoPMD
      * <img width="640" height="262" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/fromCompletionStage.o.png" alt="">
      * <p>
      * Note that the operator takes an already instantiated, running or terminated {@code CompletionStage}.
-     * If the optional is to be created per consumer upon subscription, use {@link #defer(Supplier)}
+     * If the {@code CompletionStage} is to be created per consumer upon subscription, use {@link #defer(Supplier)}
      * around {@code fromCompletionStage}:
      * <pre><code>
      * Observable.defer(() -&gt; Observable.fromCompletionStage(createCompletionStage()));

src/main/java/io/reactivex/rxjava3/core/Single.java

@@ -5598,7 +5598,7 @@ private static <T> Single<T> toSingle(@NonNull Flowable<T> source) {
      * <img width="640" height="262" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/fromCompletionStage.s.png" alt="">
      * <p>
      * Note that the operator takes an already instantiated, running or terminated {@code CompletionStage}.
-     * If the optional is to be created per consumer upon subscription, use {@link #defer(Supplier)}
+     * If the {@code CompletionStage} is to be created per consumer upon subscription, use {@link #defer(Supplier)}
      * around {@code fromCompletionStage}:
      * <pre><code>
      * Single.defer(() -&gt; Single.fromCompletionStage(createCompletionStage()));