if (headers != null) {
            final Map<String, List<String>> map = new HashMap<>();
            headers.entrySet().stream().filter(e -> e.getKey() != null).forEach(
                    e -> map.put(e.getKey().toLowerCase(Locale.ROOT), e.getValue() == null ? List.of() : List.copyOf(e.getValue())));
            this.headers = Map.copyOf(map);
        }
    }

    /**

      protected Entry<Class<? extends @NonNull B>, B> delegate() {
        return entry;
      }

      @Override
      @ParametricNullness
      public B setValue(@ParametricNullness B value) {
        cast(getKey(), value);
        return super.setValue(value);
      }
    };
  }

  @Override
  public Set<Entry<Class<? extends @NonNull B>, B>> entrySet() {

    if ((removalListener != null) && removal) {
      removalListener.onRemoval(
          RemovalNotification.create(
              ignored.getKey(), ignored.getValue().getValue(), RemovalCause.SIZE));
    }
    statsCounter.recordEviction();
    return removal;
  }

            filterSplitPackages(splitPackages);

            // Finally, print out (and fail) if we have any split packages
            for (var entry : splitPackages.entrySet()) {
                String packageName = entry.getKey();
                List<File> deps = dependencyPackages.get(packageName);
                List<String> msg = new ArrayList<>();

        if (metadataMap == null) {
            metadataMap = new HashMap<>();
        }

        ArtifactMetadata m = metadataMap.get(metadata.getKey());
        if (m != null) {
            m.merge(metadata);
        } else {
            metadataMap.put(metadata.getKey(), metadata);
        }
    }

    @Override
    public Collection<ArtifactMetadata> getMetadataList() {
        if (metadataMap == null) {

        for (Map.Entry<String, String> additional : additionalLicenses.entrySet()) {
            String category = additional.getKey().substring(0, 5);
            String family = additional.getKey().substring(5);
            matchers.add(subStringMatcher(category, family, additional.getValue()));
        }

    return new AbstractMapEntry<K, V2>() {
      @Override
      @ParametricNullness
      public K getKey() {
        return entry.getKey();
      }

      @Override
      @ParametricNullness
      public V2 getValue() {
        return transformer.transformEntry(entry.getKey(), entry.getValue());
      }
    };
  }

    return new AbstractMapEntry<K, V2>() {
      @Override
      @ParametricNullness
      public K getKey() {
        return entry.getKey();
      }

      @Override
      @ParametricNullness
      public V2 getValue() {
        return transformer.transformEntry(entry.getKey(), entry.getValue());
      }
    };
  }

public class MultimapKeySetTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  public void testKeySet() {
    for (Entry<K, V> entry : getSampleElements()) {
      assertTrue(multimap().keySet().contains(entry.getKey()));
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testKeySetContainsNullKeyPresent() {
    initMultimapWithNullKey();

     *
     * @param keyType the encryption type of the key to retrieve
     * @return the KerberosKey with the specified type, or null if not found
     */
    public KerberosKey getKey(int keyType) {
        KerberosKey serverKey = null;

        Set<Object> serverPrivateCredentials = this.subject.getPrivateCredentials();
        for (Object credential : serverPrivateCredentials) {