{* ../../docs_src/websockets/tutorial003_py39.py hl[79:81] *}

To try it out:

* Open the app with several browser tabs.
* Write messages from them.
* Then close one of the tabs.

That will raise the `WebSocketDisconnect` exception, and all the other clients will receive a message like:

```

import static org.codelibs.core.misc.AssertionUtil.assertArgumentNotNull;

import java.util.Hashtable;

import javax.naming.InitialContext;
import javax.naming.NamingException;

import org.codelibs.core.exception.NamingRuntimeException;

/**
 * Utility class for handling {@link javax.naming.InitialContext InitialContext}.
 *
 * @author higa
 */
public abstract class InitialContextUtil {

    /**

    }

    @Test
    @DisplayName("constructor accepts null principal")
    void testConstructorWithNullPrincipal(@Mock HttpServletRequest mockRequest) {
        // Constructor accepts null principal without throwing exception
        NtlmHttpServletRequest request = new NtlmHttpServletRequest(mockRequest, null);

        // getRemoteUser() will throw NPE when trying to call getName() on null principal

    }

    /**
     * Tests that the ordering of the map resembles the ordering of the input collection of artifacts.
     */
    @Test
    void testArtifactMapByVersionlessIdOrdering() throws Exception {
        List<Artifact> list = new ArrayList<>();
        list.add(newArtifact("b"));
        list.add(newArtifact("a"));
        list.add(newArtifact("c"));
        list.add(newArtifact("e"));

import org.apache.maven.project.MavenProject;
import org.apache.maven.project.artifact.InvalidDependencyVersionException;
import org.apache.maven.settings.Settings;
import org.codehaus.plexus.component.repository.exception.ComponentLookupException;

/**
 */
@Deprecated
public interface PluginManager {
    String ROLE = PluginManager.class.getName();

    /**
     * Gets the identifier of the project that could not be built. The general format of the identifier is {@code
     * <groupId>:<artifactId>:<version>} but some of these coordinates may still be unknown at the point the exception
     * is thrown so this information is merely meant to assist the user.
     *
     * @return the identifier of the project or an empty string if not known, never {@code null}
     */
    @Nonnull

    //
    // p4 ---> p3 ---> p2 ---> p1 ---> p0 --> super model
    //
    // ----------------------------------------------------------------------

    @Test
    void testProjectInheritance() throws Exception {
        MavenProject p4 = getProject(projectFile("p4"));

        assertEquals("p4", p4.getName());

        // ----------------------------------------------------------------------
        // Value inherited from p3

            try {
                fileConfigService.store(entity);
                saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
            } catch (final Exception e) {
                logger.warn("Failed to process a request.", e);
                throwValidationError(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)),

 */
@Experimental
public interface DependencyResolverResult extends Result<DependencyResolverRequest> {

    /**
     * Gets the exceptions that occurred while building the dependency graph.
     *
     * @return the exceptions that occurred, never {@code null}
     */
    @Nonnull
    List<Exception> getExceptions();

    /**
     * Gets the root node of the dependency graph.
     *

 *  Fix: Release the connection if `Authenticator` throws an exception.
 *  Fix: Change the declaration of `OkHttpClient.cache()` to return a `@Nullable Cache`. The return
    value has always been nullable but it wasn't declared properly.
 *  Fix: Reverse suppression of connect exceptions. When both a call and its retry fail, we now
    throw the initial exception which is most likely to be actionable.