[Proposal] Remote CheckReturnValue on subscribe() overloads

Proposal PR for my followup comment in #4878 at . Will close if the discussion raised there still settles on keeping them.

Author: ZacSweers

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

@@ -2318,7 +2318,6 @@ public final <E extends CompletableObserver> E subscribeWith(E observer) {
      * @return the Disposable that can be used for disposing the subscription asynchronously
      * @throws NullPointerException if either callback is null
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final Action onComplete, final Consumer<? super Throwable> onError) {
         ObjectHelper.requireNonNull(onError, "onError is null");
@@ -2345,7 +2344,6 @@ public final Disposable subscribe(final Action onComplete, final Consumer<? supe
      * @param onComplete the runnable called when this Completable completes normally
      * @return the Disposable that allows disposing the subscription
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final Action onComplete) {
         ObjectHelper.requireNonNull(onComplete, "onComplete is null");

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

@@ -14362,7 +14362,6 @@ public final Disposable subscribe() {
      *             if {@code onNext} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext) {
@@ -14393,7 +14392,6 @@ public final Disposable subscribe(Consumer<? super T> onNext) {
      *             if {@code onNext} is null, or
      *             if {@code onError} is null
      */
-    @CheckReturnValue
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError) {
@@ -14427,7 +14425,6 @@ public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super T
      *             if {@code onComplete} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
@@ -14465,7 +14462,6 @@ public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super T
      *             if {@code onSubscribe} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @BackpressureSupport(BackpressureKind.SPECIAL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError,

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

@@ -4095,7 +4095,6 @@ public final Disposable subscribe() {
      *             if {@code onSuccess} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onSuccess) {
         return subscribe(onSuccess, Functions.ON_ERROR_MISSING, Functions.EMPTY_ACTION);
@@ -4121,7 +4120,6 @@ public final Disposable subscribe(Consumer<? super T> onSuccess) {
      *             if {@code onSuccess} is null, or
      *             if {@code onError} is null
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? super Throwable> onError) {
         return subscribe(onSuccess, onError, Functions.EMPTY_ACTION);
@@ -4151,7 +4149,6 @@ public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? supe
      *             if {@code onComplete} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? super Throwable> onError,
             Action onComplete) {

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

@@ -12033,7 +12033,6 @@ public final Disposable subscribe() {
      *             if {@code onNext} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext) {
         return subscribe(onNext, Functions.ON_ERROR_MISSING, Functions.EMPTY_ACTION, Functions.emptyConsumer());
@@ -12059,7 +12058,6 @@ public final Disposable subscribe(Consumer<? super T> onNext) {
      *             if {@code onNext} is null, or
      *             if {@code onError} is null
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError) {
         return subscribe(onNext, onError, Functions.EMPTY_ACTION, Functions.emptyConsumer());
@@ -12089,7 +12087,6 @@ public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super T
      *             if {@code onComplete} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
             Action onComplete) {
@@ -12123,7 +12120,6 @@ public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super T
      *             if {@code onSubscribe} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
             Action onComplete, Consumer<? super Disposable> onSubscribe) {

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

@@ -3418,7 +3418,6 @@ public final Disposable subscribe() {
      * @throws NullPointerException
      *             if {@code onCallback} is null
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final BiConsumer<? super T, ? super Throwable> onCallback) {
         ObjectHelper.requireNonNull(onCallback, "onCallback is null");
@@ -3446,7 +3445,6 @@ public final Disposable subscribe(final BiConsumer<? super T, ? super Throwable>
      *             if {@code onSuccess} is null
      * @see <a href="http://reactivex.io/documentation/operators/subscribe.html">ReactiveX operators documentation: Subscribe</a>
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onSuccess) {
         return subscribe(onSuccess, Functions.ON_ERROR_MISSING);
@@ -3471,7 +3469,6 @@ public final Disposable subscribe(Consumer<? super T> onSuccess) {
      *             if {@code onSuccess} is null, or
      *             if {@code onError} is null
      */
-    @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(final Consumer<? super T> onSuccess, final Consumer<? super Throwable> onError) {
         ObjectHelper.requireNonNull(onSuccess, "onSuccess is null");