Iterator<Entry<E>> entryIterator = entryIterator();
    return entryIterator.hasNext() ? entryIterator.next() : null;
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    Iterator<Entry<E>> entryIterator = descendingEntryIterator();
    return entryIterator.hasNext() ? entryIterator.next() : null;
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {

        return builder()
                .session(requireNonNull(session, "session cannot be null"))
                .coordinates(requireNonNull(coordinates, "coordinates cannot be null"))
                .build();
    }

    @Nonnull
    static ArtifactResolverRequest build(
            @Nonnull Session session,

    }

    @Test
    public void test_changePassword_withBothNull() {
        // Test password change with both null
        testLdapManager.changePasswordResult = false;
        testFessConfig.ldapAdminSyncPassword = false;

        boolean result = ldapChain.changePassword(null, null);

        assertTrue(result);
        assertNull(testLdapManager.changePasswordUsername);

                null,
                dependency.getType()));
    }

    @Nonnull
    default DependencyCoordinates create(@Nonnull Session session, Plugin plugin) {
        // TODO: hard coded string
        return create(DependencyCoordinatesFactoryRequest.build(
                session, plugin.getGroupId(), plugin.getArtifactId(), plugin.getVersion(), null, null, "maven-plugin"));
    }

    @Nonnull

        assertNull(parsed.getMechanism(), "mechanism should be null when omitted");
        assertNull(parsed.getMechanismToken(), "mechanism token should be null when omitted");
        assertNull(parsed.getMechanismListMIC(), "MIC should be null when omitted");
    }

    @Test
    @DisplayName("parsing malformed token throws IOException")
    void testMalformedToken() {

    try {
      assertNull(
          "remove(null) should return null or throw NullPointerException", getMap().remove(null));
    } catch (NullPointerException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEY_QUERIES})
  public void testRemove_nullSupportedMissing() {
    assertNull("remove(null) should return null", getMap().remove(null));
    expectUnchanged();
  }

            URLStreamHandler handler = (URLStreamHandler) PROTOCOL_HANDLERS.get(protocol);
            if (handler != null) {
                return handler;
            }
            if (factory != null) {
                handler = factory.createURLStreamHandler(protocol);
            }
            if (handler == null) {
                final String path = System.getProperty(HANDLER_PKGS_PROPERTY);

        public URLStreamHandler getUrlHandler() {
            return null; // Not relevant for AbstractCIFSContext tests
        }

        @Override
        public SidResolver getSIDResolver() {
            return null; // Not relevant for AbstractCIFSContext tests
        }

        @Override
        public DfsResolver getDfs() {
            return null; // Not relevant for AbstractCIFSContext tests
        }

    }

    @Override
    public Set<Artifact> createArtifacts(MavenProject project) throws InvalidDependencyVersionException {
        return createArtifacts(artifactFactory, project.getDependencies(), null, null, project);
    }

    public static Set<Artifact> createArtifacts(
            ArtifactFactory artifactFactory,
            List<Dependency> dependencies,
            String inheritedScope,

     * @param element Configuration element name to unmarshal or {@code null} to unmarshal entire configuration.
     * @return This request for chaining, never {@code null}.
     */
    BeanConfigurationRequest setConfiguration(Object configuration, String element);

    /**
     * Returns configuration element name or {@code null}.
     *
     * @see #setConfiguration(Object, String)