* - 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) {

    return backingMap;
  }

  @SuppressWarnings("unchecked") // value could not get in if not a T
  private <T extends B> @Nullable T trustedPut(
      TypeToken<@NonNull T> type, @ParametricNullness T value) {
    return (T) backingMap.put(type, value);
  }

  @SuppressWarnings("unchecked") // value could not get in if not a T

    // We assume that all defaults are generics-safe, even if they aren't,
    // we take the risk.
    @SuppressWarnings("unchecked")
    T defaultValue = (T) defaults.getInstance(type.getRawType());
    if (defaultValue != null) {
      return defaultValue;
    }
    @SuppressWarnings("unchecked") // All arbitrary instances are generics-safe
    T arbitrary = (T) ArbitraryInstances.get(type.getRawType());

 * @author George van den Driessche
 */
@GwtIncompatible
public abstract class FeatureSpecificTestSuiteBuilder<
    B extends FeatureSpecificTestSuiteBuilder<B, G>, G> {
  @SuppressWarnings("unchecked")
  protected B self() {
    return (B) this;
  }

  // Test Data

  private @Nullable G subjectGenerator;
  // Gets run before every test.
  private Runnable setUp;

    /** Gets the weak value reference held by entry. */
    WeakValueReference<K, V, E> getValueReference();
  }

  @SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
  static <K, V, E extends InternalEntry<K, V, E>>
      WeakValueReference<K, V, E> unsetWeakValueReference() {

    }
  }

  @SuppressWarnings("unchecked") // C can only be @Nullable Character or Character
  protected @NonNull C cellValue(Character character) {
    return (C) character;
  }

  // Only safe wrt. ClassCastException. Not null-safe (can be used to test expected Table NPEs)
  @SuppressWarnings("unchecked")
  protected C nullableCellValue(@Nullable Character character) {

      size += collection.size();
    }
    return size;
  }

  @Override
  public boolean containsKey(@Nullable Object key) {
    if (unfiltered.containsKey(key)) {
      @SuppressWarnings("unchecked") // k is equal to a K, if not one itself
      K k = (K) key;
      return keyPredicate.apply(k);
    }
    return false;
  }

  @Override
  public Collection<V> removeAll(@Nullable Object key) {

    // We assume that all defaults are generics-safe, even if they aren't,
    // we take the risk.
    @SuppressWarnings("unchecked")
    T defaultValue = (T) defaults.getInstance(type.getRawType());
    if (defaultValue != null) {
      return defaultValue;
    }
    @SuppressWarnings("unchecked") // All arbitrary instances are generics-safe
    T arbitrary = (T) ArbitraryInstances.get(type.getRawType());

    }
    // same value. below comes before above
    return Boolean.compare(this instanceof AboveValue, that instanceof AboveValue);
  }

  C endpoint() {
    return endpoint;
  }

  @SuppressWarnings("unchecked") // catching CCE
  @Override
  public boolean equals(@Nullable Object obj) {
    if (obj instanceof Cut) {
      // It might not really be a Cut<C>, but we'll catch a CCE if it's not
      Cut<C> that = (Cut<C>) obj;

    public StandardKeySet() {
      super(ForwardingSortedMap.this);
    }
  }

  // unsafe, but worst case is a CCE or NPE is thrown, which callers will be expecting
  @SuppressWarnings({"unchecked", "nullness"})
  static int unsafeCompare(
      @Nullable Comparator<?> comparator, @Nullable Object o1, @Nullable Object o2) {
    if (comparator == null) {
      return ((Comparable<@Nullable Object>) o1).compareTo(o2);