*/
@NullUnmarked
@GwtIncompatible
@J2ktIncompatible
public class AbstractListeningExecutorServiceTest extends TestCase {

  public void testSubmit() throws Exception {
    /*
     * Mostly just tests that TrustedListenableFutureTask are created and run; tests for
     * TrustedListenableFutureTask should ensure that listeners are called correctly.
     */

  public HashCode hash() {
    return hasher.hash();
  }

  // Overriding close() because FilterOutputStream's close() method pre-JDK8 has bad behavior:
  // it silently ignores any exception thrown by flush(). Instead, just close the delegate stream.
  // It should flush itself if necessary.
  @Override
  public void close() throws IOException {
    out.close();
  }

        // Since it costs IO to compute this, and is done at configuration time we want to cache this if possible
        // It's safe to store this in a static variable since it's just a primitive so leaking memory isn't an issue
        if (_defaultParallel == null) {
            File cpuInfoFile = new File("/proc/cpuinfo");
            if (cpuInfoFile.exists()) {

   *     Queue<Integer>} but not a {@code Queue<Object>}).
   * @since 8.0
   */
  public static final class Builder<B> {
    /*
     * TODO(kevinb): when the dust settles, see if we still need this or can
     * just default to DEFAULT_CAPACITY.
     */
    private static final int UNSET_EXPECTED_SIZE = -1;

    private final Comparator<B> comparator;
    private int expectedSize = UNSET_EXPECTED_SIZE;

I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

As an example, let's take this function:

```python
from typing import Optional

     */
    public InvokerException(@Nullable String message, @Nullable Throwable cause) {
        super(message, cause);
    }

    /**
     * Exception for intentional exit: No message or anything will be displayed, just the
     * carried exit code will be returned from invoker {@link Invoker#invoke(InvokerRequest)} method.
     */
    public static final class ExitException extends InvokerException {
        private final int exitCode;

        ArtifactResolutionResult result = resolve(request);

        // We have collected all the problems so let's mimic the way the old code worked and just blow up right here.
        // That's right lets just let it rip right here and send a big incomprehensible blob of text at unsuspecting
        // users. Bad dog!

        resolutionErrorHandler.throwErrors(request, result);

        context.failure("Icon rendering test");
        context.warning("Icon rendering test");
        context.detail("Icon rendering test");
        context.action("Icon rendering test");

        // We just verify the methods work without throwing exceptions
        // The specific icons (Unicode vs ASCII) depend on terminal charset
    }

import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.resolver.filter.ArtifactFilter;
import org.apache.maven.wagon.events.TransferListener;

/**
 */
// Just hide the one method we want behind the RepositorySystem interface.
@Deprecated
public interface ArtifactResolver {

    ArtifactResolutionResult resolve(ArtifactResolutionRequest request);

    // The rest is deprecated

  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_REMOVE)
  /*
   * SetMultimap.asMap essentially returns a Map<K, Set<V>>; we just can't declare it that way.
   * Thus, calls like asMap().values().remove(someSet) are safe because they are comparing a set to
   * a collection of other sets.
   */
  @SuppressWarnings("CollectionUndefinedEquality")