* @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
final class AppendableWriter extends Writer {
  private final Appendable target;
  private boolean closed;

  /**
   * Creates a new writer that appends everything it writes to {@code target}.
   *
   * @param target target to which to append output
   */
  AppendableWriter(Appendable target) {
    this.target = checkNotNull(target);
  }

  /*

            @Override
            public LongAddable get() {
              return new LongAdder();
            }
          };
    } catch (Throwable t) { // we really want to catch *everything*
      supplier =
          new Supplier<LongAddable>() {
            @Override
            public LongAddable get() {
              return new PureJavaLongAddable();
            }
          };
    }

    // Here we know that:
    // * (to < from) and that both are valid indices.
    // * Everything with (index < to) should be kept.
    // * Everything with (to <= index < from) should be removed.
    // * The element with (index == from) should be kept.
    // * Everything with (index > from) has not been checked yet.

    // Check from the end of the list backwards (minimize expected cost of

   * previously stored in buffer[pivotValue]. Returns the new index of the pivot element,
   * pivotNewIndex, so that everything in [left, pivotNewIndex] is ≤ pivotValue and everything in
   * (pivotNewIndex, right] is greater than pivotValue.
   */
  private int partition(int left, int right, int pivotIndex) {
    T pivotValue = uncheckedCastNullableTToT(buffer[pivotIndex]);

      }
    }
  }

  /**
   * Returns an immediately-executable task for the calling thread to execute, sleeping as necessary
   * until one is ready. If there are no ready queues, or if other threads have everything under
   * control this will return null. If there is more than a single task ready to execute immediately
   * this will start another thread to handle that work.
   */
  fun awaitTaskToRun(): Task? {

      Thread w = thread;
      if (w != null) {
        thread = null;
        LockSupport.unpark(w);
      }
    }
  }

  /*
   * Now that we've initialized everything else, we can run the initialization code for
   * ATOMIC_HELPER. That initialization code may log after we assign to ATOMIC_HELPER.
   */

  private static final AtomicHelper ATOMIC_HELPER;

  static {

@DoNotMock("Use ImmutableList.of or another implementation")
@GwtCompatible
@SuppressWarnings("serial") // we're overriding default serialization
// TODO(kevinb): I think we should push everything down to "BaseImmutableCollection" or something,
// just to do everything we can to emphasize the "practically an interface" nature of this class.
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  /*

      Thread w = thread;
      if (w != null) {
        thread = null;
        LockSupport.unpark(w);
      }
    }
  }

  /*
   * Now that we've initialized everything else, we can run the initialization code for
   * ATOMIC_HELPER. That initialization code may log after we assign to ATOMIC_HELPER.
   */

  private static final AtomicHelper ATOMIC_HELPER;

  static {

        return (GetCheckedTypeValidator) theClass.getEnumConstants()[0];
      } catch (ClassNotFoundException
          | RuntimeException
          | Error t) { // ensure we really catch *everything*
        return weakSetValidator();
      }
    }
  }

  // TODO(cpovirk): change parameter order to match other helper methods (Class, Throwable)?

@DoNotMock("Use ImmutableList.of or another implementation")
@GwtCompatible
@SuppressWarnings("serial") // we're overriding default serialization
// TODO(kevinb): I think we should push everything down to "BaseImmutableCollection" or something,
// just to do everything we can to emphasize the "practically an interface" nature of this class.
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  /*