if !ok {
			m = make(map[string]int)
			printOnce[endpoint] = m
			if once {
				m[err.Error()]++
				peersLogAlwaysIf(ctx, err)
				return
			}
		}
		// Once is set and we are here means error was already
		// printed once.
		if once {
			return
		}
		// once not set, check if same error occurred 3 times in
		// a row, then make sure we print it to call attention.
		if m[err.Error()] > 2 {

The risk of loading untrusted checkpoints depends on the code or graph that you
are working with. When loading untrusted checkpoints, the values of the traced
variables from your model are also going to be untrusted. That means that if
your code interacts with the filesystem, network, etc. and uses checkpointed
variables as part of those interactions (ex: using a string variable to build a

        awaitTermination(0);
    }

    /**
     * Waits for the crawling process to terminate for a specified duration.
     * @param millis The maximum time to wait in milliseconds. A value of 0 means wait indefinitely.
     */
    public void awaitTermination(final long millis) {
        if (parentThread != null) {
            try {
                parentThread.join(millis);

     * Initializes the process management system with default timeout values.
     */
    public ProcessHelper() {
        // Default constructor
    }

    /**
     * Cleanup method called when the bean is destroyed.
     * Stops all running processes and cleans up resources.
     */
    @PreDestroy
    public void destroy() {
        for (final String sessionId : runningProcessMap.keySet()) {

   * each given element has increased by one since the test collection was created, and the number
   * of occurrences of all other elements has not changed.
   *
   * <p>Note: This means that a test like the following will fail if {@code collection} is a {@code
   * Set}:
   *
   * <pre>
   * collection.add(existingElement);
   * expectAdded(existingElement);</pre>
   *

        IllegalArgumentException.class,
        () -> Traverser.forGraph(createDirectedGraph()).breadthFirst('a'));
  }

  /**
   * Checks that the elements of the iterable are calculated on the fly. Concretely, that means that
   * {@link SuccessorsFunction#successors(Object)} can only be called for a subset of all nodes.
   */
  @Test
  public void forGraph_breadthFirstIterable_emptyGraph() {
    assertEqualCharNodes(

        IllegalArgumentException.class,
        () -> Traverser.forGraph(createDirectedGraph()).breadthFirst('a'));
  }

  /**
   * Checks that the elements of the iterable are calculated on the fly. Concretely, that means that
   * {@link SuccessorsFunction#successors(Object)} can only be called for a subset of all nodes.
   */
  @Test
  public void forGraph_breadthFirstIterable_emptyGraph() {
    assertEqualCharNodes(

### Locks

We have 3 different things that we synchronize on.

#### Http2Connection

This lock guards internal state of each connection. This lock is never held for blocking operations. That means that we acquire the lock, read or write a few fields and release the lock. No I/O and no application-layer callbacks.

#### Http2Stream

    @Nullable ImmutableMapEntry<K, V>[] keyTable = createEntryArray(tableSize);
    @Nullable ImmutableMapEntry<K, V>[] valueTable = createEntryArray(tableSize);
    /*
     * The cast is safe: n==entryArray.length means that we have filled the whole array with Entry
     * instances, in which case it is safe to cast it from an array of nullable entries to an array
     * of non-null entries.
     */
    @SuppressWarnings("nullness")

      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried
      barrier.await(1, SECONDS);
    } finally {
      service.shutdown();
    }
  }

  public void testRejectedExecutionThrownWithMultipleCalls() throws Exception {