@SuppressWarnings("IdentifierName")
  public static void close(@Nullable Closeable closeable, boolean swallowIOException)
      throws IOException {
    if (closeable == null) {
      return;
    }
    try {
      closeable.close();
    } catch (IOException e) {
      if (swallowIOException) {
        logger.log(Level.WARNING, "IOException thrown while closing Closeable.", e);
      } else {
        throw e;
      }
    }
  }

  /**
   * Registers the given {@code closeable} to be closed when this {@code Closer} is {@linkplain
   * #close closed}.
   *
   * @return the given {@code closeable}
   */
  // close. this word no longer has any meaning to me.
  @CanIgnoreReturnValue
  @ParametricNullness
  public <C extends @Nullable Closeable> C register(@ParametricNullness C closeable) {
    if (closeable != null) {
      stack.addFirst(closeable);

  final ExecutorService closingExecutor = newSingleThreadExecutor();

  final TestCloseable closeable1 = new TestCloseable("closeable1");
  final TestCloseable closeable2 = new TestCloseable("closeable2");
  final TestCloseable closeable3 = new TestCloseable("closeable3");
  final TestCloseable closeable4 = new TestCloseable("closeable4");

  final Waiter waiter = new Waiter();

  final ExecutorService closingExecutor = newSingleThreadExecutor();

  final TestCloseable closeable1 = new TestCloseable("closeable1");
  final TestCloseable closeable2 = new TestCloseable("closeable2");
  final TestCloseable closeable3 = new TestCloseable("closeable3");
  final TestCloseable closeable4 = new TestCloseable("closeable4");

  final Waiter waiter = new Waiter();

      this.closeable = closeable;
      this.thrown = thrown;
      this.suppressed = suppressed;
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof Suppression) {
        Suppression other = (Suppression) obj;
        return closeable.equals(other.closeable)
            && thrown.equals(other.thrown)

    ClosingFuture<Closeable> closingFuture =
        ClosingFuture.submit(closer -> closer.eventuallyClose(mockCloseable, executor), executor);
    FluentFuture<Closeable> unused = closingFuture.finishToFuture();
    assertThrows(
        IllegalStateException.class,
        () -> {
          FluentFuture<Closeable> unused2 = closingFuture.finishToFuture();
        });
  }

    ClosingFuture<Closeable> closingFuture =
        ClosingFuture.submit(closer -> closer.eventuallyClose(mockCloseable, executor), executor);
    FluentFuture<Closeable> unused = closingFuture.finishToFuture();
    assertThrows(
        IllegalStateException.class,
        () -> {
          FluentFuture<Closeable> unused2 = closingFuture.finishToFuture();
        });
  }

  }

  public void testFinishToValueAndCloser_throwsAfterCallingFinishToFuture() throws Exception {
    ClosingFuture<Closeable> closingFuture =
        ClosingFuture.submit(closer -> closer.eventuallyClose(mockCloseable, executor), executor);
    FluentFuture<Closeable> unused = closingFuture.finishToFuture();
    assertThrows(
        IllegalStateException.class,
        () ->

import com.google.common.annotations.J2ktIncompatible;
import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.io.Writer;
import org.jspecify.annotations.Nullable;

/**
 * Writer that places all output on an {@link Appendable} target. If the target is {@link Flushable}
 * or {@link Closeable}, flush()es and close()s will also be delegated to the target.
 *
 * @author Alan Green

  }

  public void testFinishToValueAndCloser_throwsAfterCallingFinishToFuture() throws Exception {
    ClosingFuture<Closeable> closingFuture =
        ClosingFuture.submit(closer -> closer.eventuallyClose(mockCloseable, executor), executor);
    FluentFuture<Closeable> unused = closingFuture.finishToFuture();
    assertThrows(
        IllegalStateException.class,
        () ->