Implement tests for memory leaks/crashes in UnmodifiableSortedMultiset, and add comments in places where the cycle could not be resolved without some refactoring.

RELNOTES=n/a
PiperOrigin-RevId: 785577286

Author: java-team-github-bot

android/guava/src/com/google/common/collect/ImmutableRangeSet.java

@@ -382,6 +382,10 @@ Object writeReplace() {
     }
   }
 
+  // TODO(b/418181860): This method creates retain cycles in J2ObjC. In order to break the cycle,
+  // there needs to be separate classes for primary and complement range set, where the primary one
+  // would hold {@code @LazyInit @RetainedWith @Nullable} reference to its complement, and the other
+  // {@code final} reference.
   @Override
   public ImmutableRangeSet<C> complement() {
     ImmutableRangeSet<C> result = complement;

android/guava/src/com/google/common/collect/UnmodifiableSortedMultiset.java

@@ -63,6 +63,10 @@ public NavigableSet<E> elementSet() {
 
   @LazyInit private transient @Nullable UnmodifiableSortedMultiset<E> descendingMultiset;
 
+  // TODO(b/418181860): This method creates retain cycles in J2ObjC. In order to break the cycle,
+  // there needs to be separate classes for primary and descending multiset, where the primary one
+  // would hold {@code @LazyInit @RetainedWith @Nullable} reference to its descending multiset, and
+  // the other {@code final} reference.
   @Override
   public SortedMultiset<E> descendingMultiset() {
     UnmodifiableSortedMultiset<E> result = descendingMultiset;

guava/src/com/google/common/collect/ImmutableRangeSet.java

@@ -381,6 +381,10 @@ Object writeReplace() {
     }
   }
 
+  // TODO(b/418181860): This method creates retain cycles in J2ObjC. In order to break the cycle,
+  // there needs to be separate classes for primary and complement range set, where the primary one
+  // would hold {@code @LazyInit @RetainedWith @Nullable} reference to its complement, and the other
+  // {@code final} reference.
   @Override
   public ImmutableRangeSet<C> complement() {
     ImmutableRangeSet<C> result = complement;

guava/src/com/google/common/collect/UnmodifiableSortedMultiset.java

@@ -63,6 +63,10 @@ public NavigableSet<E> elementSet() {
 
   @LazyInit private transient @Nullable UnmodifiableSortedMultiset<E> descendingMultiset;
 
+  // TODO(b/418181860): This method creates retain cycles in J2ObjC. In order to break the cycle,
+  // there needs to be separate classes for primary and descending multiset, where the primary one
+  // would hold {@code @LazyInit @RetainedWith @Nullable} reference to its descending multiset, and
+  // the other {@code final} reference.
   @Override
   public SortedMultiset<E> descendingMultiset() {
     UnmodifiableSortedMultiset<E> result = descendingMultiset;