* Returns a map view that associates each key with the corresponding values in the multimap.
   * Changes to the returned map, such as element removal, will update the underlying multimap. The
   * map does not support {@code setValue} on its entries, {@code put}, or {@code putAll}.
   *
   * <p>When passed a key that is present in the map, {@code asMap().get(Object)} has the same

    assertThrows(UnsupportedOperationException.class, () -> fromIterator.setValue(2));
    Entry<String, Integer> fromToArray = (Entry<String, Integer>) unmod.entries().toArray()[0];
    assertThrows(UnsupportedOperationException.class, () -> fromToArray.setValue(2));
    Entry<String, Integer>[] array = (Entry<String, Integer>[]) new Entry<?, ?>[2];

  private final Map<K, V> backingMap;

  /*
   * Per JDK: "the behavior of a map entry is undefined if the backing map has been modified after
   * the entry was returned by the iterator, except through the setValue operation on the map entry"
   * As such, this field must be cleared before every map mutation.
   *
   * Note about volatile: volatile doesn't make it safe to read from a mutable graph in one thread

        }
        final Iterator entries = map.entrySet().iterator();
        while (entries.hasNext()) {
            final Map.Entry entry = (Map.Entry) entries.next();
            entry.setValue(Collections.unmodifiableList((List) entry.getValue()));
        }
        return headerFields = Collections.unmodifiableMap(map);
    }

    @Override
    public Map getHeaderFields() {

                enqueueNotification(
                    key, hash, entryValue, valueReference.getWeight(), RemovalCause.COLLECTED);
                setValue(e, key, value, now);
                newCount = this.count; // count remains unchanged
              } else {
                setValue(e, key, value, now);
                newCount = this.count + 1;
              }
              this.count = newCount; // write-volatile

   * Returns a map view that associates each key with the corresponding values in the multimap.
   * Changes to the returned map, such as element removal, will update the underlying multimap. The
   * map does not support {@code setValue} on its entries, {@code put}, or {@code putAll}.
   *
   * <p>When passed a key that is present in the map, {@code asMap().get(Object)} has the same

      @SuppressWarnings("unchecked")
      Entry<?, @Nullable Object> nullableValueEntry = (Entry<?, @Nullable Object>) entry;
      nullableValueEntry.setValue(null);
      fail("setValue on unmodifiable Map.Entry succeeded");
    } catch (UnsupportedOperationException expected) {
    }
  }

  /**
   * Verifies that an Iterator is unmodifiable.
   *

                (et, vl) -> ((RequestHeader) et).setUpdatedTime(DfTypeUtil.toLong(vl)), "updatedTime");
        setupEpg(_epgMap, et -> ((RequestHeader) et).getValue(), (et, vl) -> ((RequestHeader) et).setValue(DfTypeUtil.toString(vl)),
                "value");
        setupEpg(_epgMap, et -> ((RequestHeader) et).getWebConfigId(),
                (et, vl) -> ((RequestHeader) et).setWebConfigId(DfTypeUtil.toString(vl)), "webConfigId");

        return value;
      }

      @Override
      public V setValue(V value) {
        throw new UnsupportedOperationException();
      }

      @SuppressWarnings("unchecked")
      @Override
      public boolean equals(@Nullable Object o) {
        if (o instanceof Entry) {
          Entry<K, V> e = (Entry<K, V>) o;
          e.setValue(value); // muhahaha!

      return new ForwardingMapEntry<C, V>() {
        @Override
        protected Entry<C, V> delegate() {
          return entry;
        }

        @Override
        public V setValue(V value) {
          return super.setValue(checkNotNull(value));
        }

        @Override
        public boolean equals(@Nullable Object object) {
          // TODO(lowasser): identify why this affects GWT tests