public static <K extends Enum<K>, V> ImmutableMap<K, V> immutableEnumMap(
      Map<K, ? extends V> map) {
    if (map instanceof ImmutableEnumMap) {
      @SuppressWarnings("unchecked") // safe covariant cast
      ImmutableEnumMap<K, V> result = (ImmutableEnumMap<K, V>) map;
      return result;
    }
    Iterator<? extends Entry<K, ? extends V>> entryItr = map.entrySet().iterator();
    if (!entryItr.hasNext()) {

  public static <K extends Enum<K>, V> ImmutableMap<K, V> immutableEnumMap(
      Map<K, ? extends V> map) {
    if (map instanceof ImmutableEnumMap) {
      @SuppressWarnings("unchecked") // safe covariant cast
      ImmutableEnumMap<K, V> result = (ImmutableEnumMap<K, V>) map;
      return result;
    }
    Iterator<? extends Entry<K, ? extends V>> entryItr = map.entrySet().iterator();
    if (!entryItr.hasNext()) {

- github.com/spaolacci/murmur3: [f09979e](https://github.com/spaolacci/murmur3/tree/f09979e)
- github.com/spf13/afero: [v1.1.2](https://github.com/spf13/afero/tree/v1.1.2)
- github.com/spf13/cast: [v1.3.0](https://github.com/spf13/cast/tree/v1.3.0)
- github.com/spf13/jwalterweatherman: [v1.0.0](https://github.com/spf13/jwalterweatherman/tree/v1.0.0)
- github.com/spf13/viper: [v1.7.0](https://github.com/spf13/viper/tree/v1.7.0)

    assertThat(response2.handshake!!.cipherSuite).isEqualTo(
      response1.handshake!!.cipherSuite,
    )
  }

  /**
   * We've had bugs where caching and cross-protocol redirects yield class cast exceptions internal
   * to the cache because we incorrectly assumed that HttpsURLConnection was always HTTPS and
   * HttpURLConnection was always HTTP; in practice redirects mean that each can do either.
   *

  /*
   * TODO(cpovirk): Can we replace makeLocalCache with a call to builder.build()? Some tests may
   * need access to LocalCache APIs, but maybe we can at least make makeLocalCache use
   * builder.build() and then cast?
   */

  private static <K, V> LocalCache<K, V> makeLocalCache(
      CacheBuilder<? super K, ? super V> builder) {
    return new LocalCache<>(builder, null);
  }

  /*
   * TODO(cpovirk): Can we replace makeLocalCache with a call to builder.build()? Some tests may
   * need access to LocalCache APIs, but maybe we can at least make makeLocalCache use
   * builder.build() and then cast?
   */

  private static <K, V> LocalCache<K, V> makeLocalCache(
      CacheBuilder<? super K, ? super V> builder) {
    return new LocalCache<>(builder, null);
  }