synchronized (mutex) {
        return delegate().toArray();
      }
    }

    @Override
    @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
    public <T extends @Nullable Object> T[] toArray(T[] a) {
      synchronized (mutex) {
        return delegate().toArray(a);
      }
    }

    private static final long serialVersionUID = 0;
  }

    }

    @Override
    public @Nullable Object[] toArray() {
      return standardToArray();
    }

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

    @Override
    public String toString() {
      return standardToString();
    }

   *
   * @param formalType is {@code Foo<formalType>} a supertype of {@code Foo<T>}?
   * @param declaration The type variable in the context of a parameterized type. Used to infer type
   *     bound when {@code formalType} is a wildcard with implicit upper bound.
   */
  private boolean is(Type formalType, TypeVariable<?> declaration) {
    if (runtimeType.equals(formalType)) {
      return true;
    }