* old Android Ice Cream Sandwich release), then this method throws an exception instead of
   * creating a directory that would be more accessible. (This behavior is new in Guava 32.0.0.
   * Previous versions would create a directory that is more accessible, as discussed in <a
   * href="https://github.com/google/guava/issues/4011">CVE-2020-8908</a>.)
   *

 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0

  SequentialExecutor(Executor executor) {
    this.executor = Preconditions.checkNotNull(executor);
  }

  /**
   * Adds a task to the queue and makes sure a worker thread is running.
   *
   * <p>If this method throws, e.g. a {@code RejectedExecutionException} from the delegate executor,
   * execution of tasks will stop until a call to this method is made.
   */
  @Override

                throw new IllegalArgumentException("maxCountLimit must be non-negative");
            }
            this.maxCountLimit = maxCountLimit;
            this.totalCount = new AtomicInteger();
            this.counters = new ConcurrentHashMap<>();
            this.problems = new ConcurrentHashMap<>();
            this.filter = requireNonNull(filter, "filter");
        }

        @Override

implies observing the write to <code>a</code>, so this program could
print an empty string too.
Worse, there is no guarantee that the write to <code>done</code> will ever
be observed by <code>main</code>, since there are no synchronization
events between the two threads.  The loop in <code>main</code> is not
guaranteed to finish.
</p>

<p>
There are subtler variants on this theme, such as this program.
</p>

<pre>

    /** The unique identifier for this dictionary item */
    protected long id;

    /**
     * Default constructor for DictionaryItem.
     * Creates a new dictionary item with default values.
     */
    public DictionaryItem() {
        // Default constructor
    }

    /**
     * Gets the unique identifier for this dictionary item.
     *
     * @return the ID of this dictionary item
     */

/*
 * © 2017 AgNO3 Gmbh & Co. KG
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

/*
 * © 2017 AgNO3 Gmbh & Co. KG
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

/*
 * © 2017 AgNO3 Gmbh & Co. KG
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0