* find it when available. When this is null, use the slow way.
   */
  @J2ktIncompatible
  @GwtIncompatible // java.lang.reflect
  @CheckForNull
  private static final Method getStackTraceElementMethod = (jla == null) ? null : getGetMethod();

  /**
   * The "getStackTraceDepth" method, only available on some JDKs so we use reflection to find it

    <jsr305.version>3.0.2</jsr305.version>
    <checker.version>3.43.0</checker.version>
    <errorprone.version>2.28.0</errorprone.version>
    <j2objc.version>3.0.0</j2objc.version>
    <!-- Empty for all JDKs but 9-12 -->
    <maven-javadoc-plugin.additionalJOptions></maven-javadoc-plugin.additionalJOptions>
    <project.build.outputTimestamp>2024-01-02T00:00:00Z</project.build.outputTimestamp>

    <jsr305.version>3.0.2</jsr305.version>
    <checker.version>3.43.0</checker.version>
    <errorprone.version>2.28.0</errorprone.version>
    <j2objc.version>3.0.0</j2objc.version>
    <!-- Empty for all JDKs but 9-12 -->
    <maven-javadoc-plugin.additionalJOptions></maven-javadoc-plugin.additionalJOptions>
    <project.build.outputTimestamp>2024-01-02T00:00:00Z</project.build.outputTimestamp>

        Class<?> optionalClass = Class.forName("java.util.Optional");
        /*
         * We don't *need* to use reflection to access Optional: It's available on all JDKs we
         * support, and Android code won't get this far, anyway, because ProcessHandle is
         * unavailable. But given how much other reflection we're using, we might as well use it

   *       <ul>
   *         <li>UNSET, meaning "null pointer"
   *         <li>one plus an index into the entries and elements array
   *       </ul>
   *   <li>another java.util.Set delegate implementation. In most modern JDKs, normal java.util hash
   *       collections intelligently fall back to a binary search tree if hash table collisions are
   *       detected. Rather than going to all the trouble of reimplementing this ourselves, we

   *       <ul>
   *         <li>UNSET, meaning "null pointer"
   *         <li>one plus an index into the entries and elements array
   *       </ul>
   *   <li>another java.util.Set delegate implementation. In most modern JDKs, normal java.util hash
   *       collections intelligently fall back to a binary search tree if hash table collisions are
   *       detected. Rather than going to all the trouble of reimplementing this ourselves, we

    // We can continue if it's 1.8, and we can continue if it's an integer in [9, 20).
    if (javaVersion != null && javaVersion >= 20) {
      // TODO(b/261217224, b/361604053): Make this test work under newer JDKs.
      return;
    }
    TimedWaiterThread thread = new TimedWaiterThread(new AbstractFuture<Object>() {}, 2, SECONDS);
    thread.start();
    thread.awaitWaiting();