return super.cancel(mayInterruptIfRunning);
    }
  }

  FluentFuture() {}

  /**
   * Converts the given {@code ListenableFuture} to an equivalent {@code FluentFuture}.
   *
   * <p>If the given {@code ListenableFuture} is already a {@code FluentFuture}, it is returned
   * directly. If not, it is wrapped in a {@code FluentFuture} that delegates all calls to the
   * original {@code ListenableFuture}.
   */

    ListenableFuture<String> f = FluentFuture.from(SettableFuture.create());
    assertThat(FluentFuture.from(f)).isSameInstanceAs(f);
  }

  public void testFromNonFluentFuture() throws Exception {
    ListenableFuture<String> f =
        new SimpleForwardingListenableFuture<String>(immediateFuture("a")) {};
    verify(!(f instanceof FluentFuture));
    assertThat(FluentFuture.from(f).get()).isEqualTo("a");

import com.google.common.annotations.J2ktIncompatible;
import org.jspecify.annotations.Nullable;

/**
 * Hidden superclass of {@link FluentFuture} that provides us a place to declare special GWT
 * versions of the {@link FluentFuture#catching(Class, com.google.common.base.Function)
 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */
@GwtCompatible
@J2ktIncompatible // Super-sourced

  private final CloseableList closeables;
  private final FluentFuture<V> future;

  private ClosingFuture(ListenableFuture<V> future) {
    this(future, new CloseableList());
  }

  private ClosingFuture(ListenableFuture<V> future, CloseableList closeables) {
    this.future = FluentFuture.from(future);
    this.closeables = closeables;
  }

  /**

     * should throw IllegalStateException only when they use static state.
     *
     * Why do we deviate here? The answer: We want for fluentFuture.getDone() to throw the same
     * exception as Futures.getDone(fluentFuture).
     */
    checkState(future.isDone(), "Future was expected to be done: %s", future);
    return getUninterruptibly(future);
  }

  /**