minThresholdPosition = pivotNewIndex;
      } else {
        break;
      }
      iterations++;
      if (iterations >= maxIterations) {
        @SuppressWarnings("nullness") // safe because we pass sort() a range that contains real Ts
        T[] castBuffer = (T[]) buffer;
        // We've already taken O(k log k), let's make sure we don't take longer than O(k log k).

   *
   * So we use uncheckedCastNullableTToT here. This is a weird usage of that method: The method is
   * documented as being for use with type parameters that have parametric nullness. But Converter's
   * type parameters do not. Still, we use it here so that we can suppress a warning at a smaller
   * level than the whole method but without performing a runtime null check. That way, we can still

    clearCache();
    backingMap.clear();
  }

  @Nullable V get(Object key) {
    checkNotNull(key);
    V value = getIfCached(key);
    // TODO(b/192579700): Use a ternary once it no longer confuses our nullness checker.
    if (value == null) {
      return getWithoutCaching(key);
    } else {
      return value;
    }
  }

  final @Nullable V getWithoutCaching(Object key) {
    checkNotNull(key);

      return (delegate != null)
          ? delegate.keySet().toArray()
          : ObjectArrays.copyAsObjectArray(requireKeys(), 0, size);
    }

    @Override
    @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
    public <T extends @Nullable Object> T[] toArray(T[] a) {
      if (needsAllocArrays()) {
        if (a.length > 0) {

   * Ideally, this class would have exposed only constructors that require a non-null cause. See
   * https://github.com/jspecify/jspecify-reference-checker/blob/61aafa4ae52594830cfc2d61c8b113009dbdb045/src/main/java/com/google/jspecify/nullness/NullSpecTransfer.java#L789
   * and https://github.com/jspecify/jspecify/issues/490.
   *
   * (That would also have ensured that its cause was always an Error, rather than possibly another

     * non-null elements, so we can treat it as a plain `Object[]`.
     */
    @SuppressWarnings("nullness")
    Object[] result = ObjectArrays.toArrayImpl(this);
    return result;
  }

  @Override
  @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
  public <T extends @Nullable Object> T[] toArray(T[] other) {

   * Verifies that the specified expected result is always produced by collecting the specified
   * inputs, regardless of how the elements are divided.
   */
  @SafeVarargs
  @CanIgnoreReturnValue
  @SuppressWarnings("nullness") // TODO(cpovirk): Remove after we fix whatever the bug is.
  public final CollectorTester<T, A, R> expectCollects(R expectedResult, T... inputs) {
    List<T> list = Arrays.asList(inputs);

          ? NullnessAnnotationReader.FROM_DECLARATION_AND_TYPE_USE_ANNOTATIONS
          : NullnessAnnotationReader.FROM_DECLARATION_ANNOTATIONS_ONLY;

  /**
   * Looks for declaration nullness annotations and, if supported, type-use nullness annotations.
   *
   * <p>Under Android VMs, the methods for retrieving type-use annotations don't exist. This means

  public Object[] toArray() {
    /*
     * If we could, we'd declare the no-arg `Collection.toArray()` to return "Object[] but elements
     * have the same nullness as E." Since we can't, we declare it to return nullable elements, and
     * we can override it in our non-null-guaranteeing subtypes to present a better signature to
     * their users.
     *

 * in com.google.guava:guava differs from the "frozen" copy in the listenablefuture artifact. This
 * could in principle cause problems for some users. Still, we expect that the benefits of the
 * nullness annotations in particular will outweigh the costs. (And it's worth noting that we have
 * released multiple ListenableFuture.class files that are not byte-for-byte compatible even from