return new ArrayBlockingQueue<>(capacity);
  }

  // ArrayDeque

  /**
   * Creates an empty {@code ArrayDeque}.
   *
   * @since 12.0
   */
  public static <E> ArrayDeque<E> newArrayDeque() {
    return new ArrayDeque<>();
  }

  /**
   * Creates an {@code ArrayDeque} containing the elements of the specified iterable, in the order

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Queue;

          return endOfData();
        }
      };
    }

    final Iterator<N> postOrder(Iterator<? extends N> startNodes) {
      Deque<N> ancestorStack = new ArrayDeque<>();
      Deque<Iterator<? extends N>> horizon = new ArrayDeque<>();
      horizon.add(startNodes);
      return new AbstractIterator<N>() {
        @Override
        @CheckForNull
        protected N computeNext() {

import com.google.errorprone.annotations.concurrent.GuardedBy;
import com.google.errorprone.annotations.concurrent.LazyInit;
import com.google.j2objc.annotations.RetainedWith;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.concurrent.Executor;
import java.util.concurrent.RejectedExecutionException;
import java.util.logging.Level;
import javax.annotation.CheckForNull;

/**

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Queue;

import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Queue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

    setImplementation(Deque.class, ArrayDeque.class);
    setImplementation(OutputStream.class, ByteArrayOutputStream.class);
    setImplementation(PrintStream.class, Dummies.InMemoryPrintStream.class);
    setImplementation(PrintWriter.class, Dummies.InMemoryPrintWriter.class);
    setImplementation(Queue.class, ArrayDeque.class);
    setImplementation(Random.class, Dummies.DeterministicRandom.class);

    setImplementation(Deque.class, ArrayDeque.class);
    setImplementation(OutputStream.class, ByteArrayOutputStream.class);
    setImplementation(PrintStream.class, Dummies.InMemoryPrintStream.class);
    setImplementation(PrintWriter.class, Dummies.InMemoryPrintWriter.class);
    setImplementation(Queue.class, ArrayDeque.class);
    setImplementation(Random.class, Dummies.DeterministicRandom.class);

import com.google.common.annotations.VisibleForTesting;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.Closeable;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.logging.Level;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.j2objc.annotations.Weak;
import com.google.j2objc.annotations.WeakOuter;
import java.util.AbstractQueue;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.ConcurrentModificationException;
import java.util.Iterator;