* hashmaps. Using a static ThreadLocal to avoid that overhead would mean that different
   * ExecutionSequencer objects interfere with each other, which would be undesirable, in addition
   * to increasing the memory footprint of every thread that interacted with it. In order to release
   * entries in thread-specific maps when the ThreadLocal object itself is no longer referenced,

   * hashmaps. Using a static ThreadLocal to avoid that overhead would mean that different
   * ExecutionSequencer objects interfere with each other, which would be undesirable, in addition
   * to increasing the memory footprint of every thread that interacted with it. In order to release
   * entries in thread-specific maps when the ThreadLocal object itself is no longer referenced,

  // ClasLoader via its AccessControlContext. It does not seem to be possible to make a
  // URLClassLoader without capturing this reference, and it probably would not be desirable for
  // security reasons anyway. Therefore, the FRQ.close() method provides a way to stop the thread
  // explicitly. This test checks that calling that method does allow an app's ClassLoader to be

 * </ul>
 *
 * <p>Summarizing the last two points: "equal yield equal <i>always</i>; unequal yield unequal
 * <i>often</i>." This is the most important characteristic of all hash functions.
 *
 * <h3>Desirable properties</h3>
 *
 * <p>A high-quality hash function strives for some subset of the following virtues:
 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>

 * </ul>
 *
 * <p>Summarizing the last two points: "equal yield equal <i>always</i>; unequal yield unequal
 * <i>often</i>." This is the most important characteristic of all hash functions.
 *
 * <h3>Desirable properties</h3>
 *
 * <p>A high-quality hash function strives for some subset of the following virtues:
 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>

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  /**
   * The current state of the service. This should be written with the lock held but can be read
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   * methods like {@link #state}, {@link #failureCause} and notably {@link #toString} can be run
   * without grabbing the lock.
   *

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If it is not possible or desirable to put the notice in a particular file, then
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  /**
   * The current state of the service. This should be written with the lock held but can be read
   * without it because it is an immutable object in a volatile field. This is desirable so that
   * methods like {@link #state}, {@link #failureCause} and notably {@link #toString} can be run
   * without grabbing the lock.
   *