public interface FinalizationPredicate {
    boolean isDone();
  }

  /**
   * Waits until the given weak reference is cleared, invoking the garbage collector as necessary to
   * try to ensure that this will happen.
   *
   * <p>This is a convenience method, equivalent to:
   *
   * {@snippet :
   * awaitDone(new FinalizationPredicate() {
   *   public boolean isDone() {

 */

package com.google.common.testing;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;

import com.google.common.testing.GcFinalization.FinalizationPredicate;
import com.google.common.util.concurrent.SettableFuture;
import java.lang.ref.WeakReference;
import java.util.WeakHashMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicBoolean;

 */

package com.google.common.testing;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;

import com.google.common.testing.GcFinalization.FinalizationPredicate;
import com.google.common.util.concurrent.SettableFuture;
import java.lang.ref.WeakReference;
import java.util.WeakHashMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicBoolean;

  public interface FinalizationPredicate {
    boolean isDone();
  }

  /**
   * Waits until the given weak reference is cleared, invoking the garbage collector as necessary to
   * try to ensure that this will happen.
   *
   * <p>This is a convenience method, equivalent to:
   *
   * {@snippet :
   * awaitDone(new FinalizationPredicate() {
   *   public boolean isDone() {

    out.close();

    // Make sure that finalize deletes the file
    out = null;

    // times out and throws RuntimeException on failure
    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override
          public boolean isDone() {
            return !file.exists();
          }
        });
  }