run: ./gradlew test -Dtest.java.version=21

  testopenjdklatest:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v5

      - name: Configure JDKs
        uses: actions/setup-java@v5
        with:
          distribution: 'zulu'
          java-version: |
            11
            17
            24

      - name: Allow incompatible JVM versions

   *       <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 apparently have only one <jdk> per execution: Others are silently ignored :(
            To properly test this, you need to remove existing toolchains:
            rm -rf ~/.m2/jdks/ ~/.m2/toolchains.xml
            (But don't run that if you have put something into ~/.m2/toolchains.xml yourself.)
            -->
            <execution>
              <id>download-24-and-surefire-version</id>

            <!--
            We can apparently have only one <jdk> per execution: Others are silently ignored :(
            To properly test this, you need to remove existing toolchains:
            rm -rf ~/.m2/jdks/ ~/.m2/toolchains.xml
            (But don't run that if you have put something into ~/.m2/toolchains.xml yourself.)
            -->
            <execution>
              <id>download-24-and-surefire-version</id>

   *         <li>UNSET, meaning "null pointer"
   *         <li>one plus an index into the keys, values, and entries arrays
   *       </ul>
   *   <li>another java.util.Map 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();

   *         <li>UNSET, meaning "null pointer"
   *         <li>one plus an index into the keys, values, and entries arrays
   *       </ul>
   *   <li>another java.util.Map 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();

          <type>String</type>
          <description>
            Specifies that this profile will be activated when a matching JDK is detected.
            For example, {@code 1.4} only activates on JDKs versioned 1.4,
            while {@code !1.4} matches any JDK that is not version 1.4. Ranges are supported too:
            {@code [1.5,)} activates when the JDK is 1.5 minimum.
          </description>
        </field>