* return type is plain FilenameFilter. If we made such a change, then the annotation we choose
   * here would have no significance to end users, who would be forced to conform to the signature
   * used in FilenameFilter.)
   */
  @Override
  public boolean accept(File dir, String fileName) {
    return pattern.matcher(fileName).matches();
  }

@J2ktIncompatible // Emulated
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class DirectExecutorService extends AbstractListeningExecutorService {

  /** Lock used whenever accessing the state variables (runningTasks, shutdown) of the executor */
  private final Object lock = new Object();

  /*
   * Conceptually, these two variables describe the executor being in

  @SuppressWarnings("RedundantOverride")
  @Override
  @J2ktIncompatible // serialization
  @GwtIncompatible // serialization
  Object writeReplace() {
    return super.writeReplace();
  }

  // No longer used for new writes, but kept so that old data can still be read.
  @GwtIncompatible // serialization
  @J2ktIncompatible
  @SuppressWarnings("unused")
  private static class SerializedForm<V> implements Serializable {

import java.util.Collection;
import java.util.Map;
import javax.annotation.CheckForNull;

/**
 * An implementation of ImmutableMultiset backed by a JDK Map and a list of entries. Used to protect
 * against hash flooding attacks.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableMultiset<E> extends ImmutableMultiset<E> {

     */
    DfsResolver getDfs ();


    /**
     * @return the SID resolver for this context
     */
    SidResolver getSIDResolver ();


    /**
     * 
     * @return the used credentials
     */
    Credentials getCredentials ();


    /**
     * @return an URL handler using this context
     */
    URLStreamHandler getUrlHandler ();


    /**

                  and/or service. The controller will use the pool with lowest value
                  of priority in case of multiple matches. A pool with no priority
                  set will be used only if the pools with priority can't be used.
                  If multiple matching IPAddressPools are available it will check

import java.util.Date;
import java.util.Locale;
import java.util.Properties;

import org.apache.maven.jline.MessageUtils;
import org.apache.maven.utils.Os;
import org.slf4j.Logger;

/**
 * Utility class used to report errors, statistics, application version info, etc.
 *
 */
public final class CLIReportingUtils {
    // CHECKSTYLE_OFF: MagicNumber
    public static final long MB = 1024 * 1024;

    private static final Pattern FILTER_2 = Pattern.compile("[._-]");
    private static final Pattern FILTER_3 = Pattern.compile("\\."); // used for split now

    @Override
    public boolean isActive(Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
        Activation activation = profile.getActivation();

        if (activation == null) {
            return false;

The way to describe this in OpenAPI, is to mark that field as **required**, because it will always be there.

Because of that, the JSON Schema for a model can be different depending on if it's used for **input or output**:

* for **input** the `description` will **not be required**
* for **output** it will be **required** (and possibly `None`, or in JSON terms, `null`)

### Model for Output in Docs

    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("I bet you didn't think Thread.interrupt could throw");
    // We need to wait for the runner to exit.  It used to be that the runner would get stuck in the
    // busy loop when interrupt threw.
    runner.join(SECONDS.toMillis(10));
  }

  static final class BrokenChannel extends AbstractInterruptibleChannel {
    @Override