assertEquals(0, multimap().keys().count(null));
  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testKeysWithNullKey() {
    resetContainer(mapEntry((K) null, v0()), mapEntry((K) null, v1()), mapEntry(k1(), v0()));
    Multiset<K> keys = multimap().keys();
    assertEquals(2, keys.count(null));
    assertEquals(1, keys.count(k1()));
    assertEquals(3, keys.size());

        if (metadata.getVersioning() == null) {
            DateFormat utcDateFormatter = new SimpleDateFormat(DEFAULT_SNAPSHOT_TIMESTAMP_FORMAT);
            utcDateFormatter.setCalendar(new GregorianCalendar());
            utcDateFormatter.setTimeZone(DEFAULT_SNAPSHOT_TIME_ZONE);

            snapshot = new Snapshot();
            snapshot.setBuildNumber(buildNumber != null ? buildNumber : getBuildNumber(recessive) + 1);

    }

    /**
     * @deprecated use {@link #getPomFile()}
     */
    @Deprecated
    public String getPomLocation() {
        if (getPomFile() != null) {
            return getPomFile().getAbsolutePath();
        } else {
            return "null";
        }
    }

    public String getProjectId() {
        return projectId;
    }

    public List<ProjectBuildingResult> getResults() {

        .testEquals();
  }

  @AndroidIncompatible // Android forbids null parent ClassLoader
  public void testClassPathEntries_emptyURLClassLoader_noParent() {
    assertThat(ClassPath.getClassPathEntries(new URLClassLoader(new URL[0], null)).keySet())
        .isEmpty();
  }

  @AndroidIncompatible // Android forbids null parent ClassLoader
  public void testClassPathEntries_urlClassLoader_noParent() throws Exception {

        sb.append("   layout: ").append(layout != null ? layout : "none").append('\n');

        if (snapshots != null) {
            sb.append("snapshots: [enabled => ").append(snapshots.isEnabled());
            sb.append(", update => ").append(snapshots.getUpdatePolicy()).append("]\n");
        }

        if (releases != null) {
            sb.append(" releases: [enabled => ").append(releases.isEnabled());

            getMap()
                .computeIfAbsent(
                    null,
                    k -> {
                      assertNull(k);
                      return v3();
                    }));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported computeIfAbsent(null, function)");
  }

        if (deploymentTimestamp == null) {
            deploymentTimestamp = getUtcDateFormatter().format(new Date());
        }
        return deploymentTimestamp;
    }

    @Override
    protected String constructVersion(Versioning versioning, String baseVersion) {
        String version = null;
        Snapshot snapshot = versioning.getSnapshot();
        if (snapshot != null) {

    builder = builder.delete(null)
    builder = builder.put(requestBody)
    builder = builder.patch(requestBody)
    builder = builder.method("", requestBody)
    builder = builder.method("", null)
    builder = builder.tag("")
    builder = builder.tag(null)
    builder = builder.tag(String::class.java, "")
    builder = builder.tag(String::class.java, null)
    val request: Request = builder.build()

      val sslContextClass = Class.forName("sun.security.ssl.SSLContextImpl")
      val context = readFieldOrNull(sslSocketFactory, sslContextClass, "context") ?: return null
      readFieldOrNull(context, X509TrustManager::class.java, "trustManager")
    } catch (e: ClassNotFoundException) {
      null
    } catch (e: RuntimeException) {
      // Throws InaccessibleObjectException (added in JDK9) on JDK 17 due to

   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {
    try {
      assertFalse(message, getMap().containsKey(null));
    } catch (NullPointerException tolerated) {