if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  @ParametricNullness
  public K lastKey() {
    Entry<K, V> entry = lastEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  public @Nullable Entry<K, V> lowerEntry(@ParametricNullness K key) {

        final Iterator entries = requestProperties.entrySet().iterator();
        while (entries.hasNext()) {
            final Map.Entry entry = (Map.Entry) entries.next();
            if (key.equalsIgnoreCase((String) entry.getKey())) {
                entry.setValue(values);
                found = true;
                break;
            }
        }
        if (!found) {
            requestProperties.put(key, values);
        }

                          return next.getValue();
                        }

                        @Override
                        public String getKey() {
                          return next.getKey();
                        }

                        @Override
                        public boolean equals(@Nullable Object obj) {
                          return next.equals(obj);

    }

    @Override
    public boolean matchesRequirements(Map<String, String> requirements) {
        for (Map.Entry<String, String> requirement : requirements.entrySet()) {
            String key = requirement.getKey();

            RequirementMatcher matcher = provides.get(key);

            if (matcher == null) {
                getLog().debug("Toolchain {} is missing required property: {}", this, key);
                return false;

            }

            String result = template;
            if (paramMap != null) {
                for (Map.Entry<String, Object> entry : paramMap.entrySet()) {
                    String key = entry.getKey();
                    Object value = entry.getValue();

                    // Handle nested properties
                    if (key.contains(".")) {
                        // Simple nested property handling for testing

                          return next.getValue();
                        }

                        @Override
                        public String getKey() {
                          return next.getKey();
                        }

                        @Override
                        public boolean equals(@Nullable Object obj) {
                          return next.equals(obj);

      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() {

 */
final class ImmutableEnumMap<K, V> extends ForwardingImmutableMap<K, V> {
  static <K, V> ImmutableMap<K, V> asImmutable(Map<K, V> map) {
    for (Entry<K, V> entry : checkNotNull(map).entrySet()) {
      checkNotNull(entry.getKey());
      checkNotNull(entry.getValue());
    }
    return new ImmutableEnumMap<K, V>(map);
  }

  private ImmutableEnumMap(Map<? extends K, ? extends V> delegate) {
    super(delegate);
  }

          }

          @Override
          public K next() {
            Entry<K, V> entry = entryIterator.next(); // store local reference for thread-safety
            cacheEntry = entry;
            return entry.getKey();
          }
        };
      }

      @Override
      public int size() {
        return backingMap.size();
      }

      @Override
      public boolean contains(@Nullable Object key) {

    super(key, value);
    checkEntryNotNull(key, value);
  }

  // Redeclare methods to make them `final`, just to be extra-safe.

  @Override
  @ParametricNullness
  public final K getKey() {
    return super.getKey();
  }

  @Override
  @ParametricNullness
  public final V getValue() {
    return super.getValue();
  }

  @Override
  @ParametricNullness