private final CountDownLatch returned = new CountDownLatch(1);
    private Object proxy;

    @SuppressWarnings("unchecked") // proxy for a generic class
    <V> Callable<V> waitFor(Callable<V> callable) {
      return waitFor(callable, Callable.class);
    }

    @SuppressWarnings("unchecked") // proxy for a generic class
    <V> ClosingCallable<V> waitFor(ClosingCallable<V> closingCallable) {

  }

  @Override
  public final BiMap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

  }

  @Override
  public final SetMultimap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

   * - https://github.com/jspecify/jdk/commit/71d826792b8c7ef95d492c50a274deab938f2552
   */
  /*
   * TODO(cpovirk): Is the unchecked cast avoidable? Would System.arraycopy be similarly fast (if
   * likewise not type-checked)? Could our single caller do something different?
   */
  @SuppressWarnings({"nullness", "unchecked"})
  static <T extends @Nullable Object> T[] copy(Object[] source, int from, int to, T[] arrayOfType) {

         * doesn't recognize this kind of cast as unchecked cast. Neither does
         * Eclipse 3.4. Right now, this suppression is mostly unnecessary.
         */
        @SuppressWarnings("unchecked")
        MultiExceptionListIterator multiExceptionListIterator =
            (MultiExceptionListIterator) reference;
        multiExceptionListIterator.promoteToNext(targetReturnValueFromNext);
      }

  }

  @Override
  public final SetMultimap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

                  // Other tests will verify what real, warning-free usage looks like
                  // but here we have to do some serious fudging
                  @Override
                  @SuppressWarnings({"unchecked", "rawtypes"})
                  public Map<TypeToken, Object> create(Object... elements) {
                    MutableTypeToInstanceMap<Object> map = new MutableTypeToInstanceMap<>();

        // These come from Entry<K, Collection<V>>> objects somewhere.
        @SuppressWarnings("unchecked")
        K key = (K) entry.getKey();
        keySet.add(key);
        for (Object v : (Collection<?>) entry.getValue()) {
          // These come from Entry<K, Collection<V>>> objects somewhere.
          @SuppressWarnings("unchecked")
          V value = (V) v;
          builder.add(mapEntry(key, value));
        }
      }

    override val token: KtLifetimeToken,
    override val firSymbol: FirVariableSymbol<*>,
    override val firSymbolBuilder: KtSymbolByFirBuilder,
) : KtFirVariableLikeSignature<S>() {
    @Suppress("UNCHECKED_CAST")
    override val symbol: S
        get() = withValidityAssertion { firSymbol.buildSymbol(firSymbolBuilder) as S }
    override val returnType: KtType
        get() = withValidityAssertion { symbol.returnType }

          "Invokable is known to return " + getReturnType() + ", not " + returnType);
    }
    @SuppressWarnings("unchecked") // guarded by previous check
    Invokable<T, R1> specialized = (Invokable<T, R1>) this;
    return specialized;
  }

  @SuppressWarnings("unchecked") // The declaring class is T's raw class, or one of its supertypes.
  @Override
  public final Class<? super T> getDeclaringClass() {