$ javap java.lang.StableValue     (25.0.4.1+1-LTS)
Compiled from "StableValue.java"
public interface java.lang.StableValue<T> {
  public abstract boolean trySet(T);
  public abstract T orElse(T);
  public abstract T orElseThrow();
  public abstract boolean isSet();
  public abstract T orElseSet(java.util.function.Supplier<? extends T>);
  public abstract void setOrThrow(T);
  public abstract boolean equals(java.lang.Object);
  public abstract int hashCode();
  public static <T> java.lang.StableValue<T> of();
  public static <T> java.lang.StableValue<T> of(T);
  public static <T> java.util.function.Supplier<T> supplier(java.util.function.Supplier<? extends T>);
  public static <R> java.util.function.IntFunction<R> intFunction(int, java.util.function.IntFunction<? extends R>);
  public static <T, R> java.util.function.Function<T, R> function(java.util.Set<? extends T>, java.util.function.Function<? super T, ? extends R>);
  public static <E> java.util.List<E> list(int, java.util.function.IntFunction<? extends E>);
  public static <K, V> java.util.Map<K, V> map(java.util.Set<K>, java.util.function.Function<? super K, ? extends V>);
}

$ javap java.lang.LazyConstant     (26.0.2.1+1)
Compiled from "LazyConstant.java"
public interface java.lang.LazyConstant<T> extends java.util.function.Supplier<T> {
  public abstract T orElse(T);
  public abstract T get();
  public abstract boolean isInitialized();
  public abstract boolean equals(java.lang.Object);
  public abstract int hashCode();
  public abstract java.lang.String toString();
  public static <T> java.lang.LazyConstant<T> of(java.util.function.Supplier<? extends T>);
}

$ javap java.lang.LazyConstant     (27+35)
Compiled from "LazyConstant.java"
public interface java.lang.LazyConstant<T> extends java.util.function.Supplier<T> {
  public abstract T get();
  public abstract boolean equals(java.lang.Object);
  public abstract int hashCode();
  public abstract java.lang.String toString();
  public static <T> java.lang.LazyConstant<T> of(java.util.function.Supplier<? extends T>);
}

$ javap java.util.List | grep ofLazy     (26.0.2.1+1)
  public static <E> java.util.List<E> ofLazy(int, java.util.function.IntFunction<? extends E>);
$ javap java.util.Map | grep ofLazy     (26.0.2.1+1)
  public static <K, V> java.util.Map<K, V> ofLazy(java.util.Set<? extends K>, java.util.function.Function<? super K, ? extends V>);
$ javap java.util.Set | grep ofLazy     (26.0.2.1+1)

$ javap java.util.List | grep ofLazy     (27+35)
  public static <E> java.util.List<E> ofLazy(int, java.util.function.IntFunction<? extends E>);
$ javap java.util.Map | grep ofLazy     (27+35)
  public static <K, V> java.util.Map<K, V> ofLazy(java.util.Set<? extends K>, java.util.function.Function<? super K, ? extends V>);
$ javap java.util.Set | grep ofLazy     (27+35)
  public static <E> java.util.Set<E> ofLazy(java.util.Set<? extends E>, java.util.function.Predicate<? super E>);

$ javac --enable-preview --release 25 src/StableValue25.java && java --enable-preview StableValue25     (25.0.4.1+1-LTS)
  [load] configuration
CONFIG.get(): loaded
CONFIG.get(): loaded
  [compute] orElseSet
lazy(): computed
lazy(): computed
  [element] 2
LIST.get(2): v2

$ javac --enable-preview --release 26 broken/StillStable.java     (26.0.2.1+1)
broken/StillStable.java:3: error: cannot find symbol
    static final StableValue<String> CONFIG = StableValue.of();
                 ^
  symbol:   class StableValue
  location: class StillStable
broken/StillStable.java:3: error: cannot find symbol
    static final StableValue<String> CONFIG = StableValue.of();
                                              ^
  symbol:   variable StableValue
  location: class StillStable
2 errors
exit=1

$ javac --enable-preview --release 27 broken/StillStable.java     (27+35)
broken/StillStable.java:3: error: cannot find symbol
    static final StableValue<String> CONFIG = StableValue.of();
                 ^
  symbol:   class StableValue
  location: class StillStable
broken/StillStable.java:3: error: cannot find symbol
    static final StableValue<String> CONFIG = StableValue.of();
                                              ^
  symbol:   variable StableValue
  location: class StillStable
2 errors
exit=1

$ javac --enable-preview --release 26 broken/RemovedApi.java     (26.0.2.1+1)
exit=0

$ javac --enable-preview --release 27 broken/RemovedApi.java     (27+35)
broken/RemovedApi.java:4: error: cannot find symbol
        System.out.println(c.isInitialized());   // exists on JDK 26, removed in 27
                            ^
  symbol:   method isInitialized()
  location: variable c of type LazyConstant<String>
broken/RemovedApi.java:5: error: cannot find symbol
        System.out.println(c.orElse("fallback")); // exists on JDK 26, removed in 27
                            ^
  symbol:   method orElse(String)
  location: variable c of type LazyConstant<String>
2 errors
exit=1

$ javac --enable-preview --release 27 broken/ReassignInSupplier.java     (27+35)
broken/ReassignInSupplier.java:5: error: cannot find symbol
        c.set("y");
         ^
  symbol:   method set(String)
  location: variable c of type LazyConstant<String>
1 error
exit=1