* #startUp} and {@link #shutDown}) will never run concurrently. Notably, if any execution of {@link
 * #runOneIteration} takes longer than its schedule defines, then subsequent executions may start
 * late. Also, all life cycle methods are executed with a lock held, so subclasses can safely modify
 * shared state without additional synchronization necessary for visibility to later executions of

 * #startUp} and {@link #shutDown}) will never run concurrently. Notably, if any execution of {@link
 * #runOneIteration} takes longer than its schedule defines, then subsequent executions may start
 * late. Also, all life cycle methods are executed with a lock held, so subclasses can safely modify
 * shared state without additional synchronization necessary for visibility to later executions of

- Removed a warning related to Linux user namespaces and kernel version. Previously, if the feature gate `UserNamespacesSupport` was enabled, the kubelet warned when detecting a Linux kernel version earlier than 6.3.0. While user namespace support generally requires kernel 6.3 or newer, it can also work on older kernels. ([#130243](https://github.com/kubernetes/kubernetes/pull/130243), [@rata](https://github.com/rata))

    }

    private static char[] nines() {
      char[] nines = new char[ZEROES.length()];
      for (int i = 0; i < ZEROES.length(); i++) {
        nines[i] = (char) (ZEROES.charAt(i) + 9);
      }
      return nines;
    }

    static final CharMatcher INSTANCE = new Digit();

    private Digit() {
      super("CharMatcher.digit()", zeroes(), nines());
    }
  }

- Removed a warning around Linux user namespaces and kernel version. If the feature gate `UserNamespacesSupport` was enabled, the kubelet previously warned when detecting a Linux kernel version earlier than 6.3.0. User namespace support on Linux typically does still need kernel 6.3 or newer, but it can work in older kernels too. ([#131784](https://github.com/kubernetes/kubernetes/pull/131784), [@rata](https://github.com/rata)) [SIG Node]...

    checkState(boxedBoolean.booleanValue(), "", s);
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {
    /*
     * Don't bother testing: Preconditions defines a bunch of methods that accept a template (or
     * even entire message) that simultaneously:
     *
     * - _shouldn't_ be null, so we don't annotate it with @Nullable
     *

    checkState(boxedBoolean.booleanValue(), "", s);
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {
    /*
     * Don't bother testing: Preconditions defines a bunch of methods that accept a template (or
     * even entire message) that simultaneously:
     *
     * - _shouldn't_ be null, so we don't annotate it with @Nullable
     *

 * loading), and fewer <a
 * href="https://github.com/google/guava/issues?q=is%3Aopen+is%3Aissue+label%3Apackage%3Dcache+label%3Atype%3Ddefect">bugs</a>.
 *
 * <p>Caffeine defines its own interfaces (<a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/Cache.html">{@code
 * Cache}</a>, <a

    Collection<Number> nums = ImmutableSet.of();
    Predicate<Number> p1 = Predicates.in(nums);
    Predicate<Object> p2 = Predicates.<Object>in(nums);
    // The next two lines are not expected to compile.
    // Predicate<Integer> p3 = Predicates.in(nums);
    // Predicate<Integer> p4 = Predicates.<Integer>in(nums);
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester

- Kubeadm: switched the validation check for Linux kernel version to throw warnings instead of errors. ([#131919](https://github.com/kubernetes/kubernetes/pull/131919), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle and Node]