}
    },
    FORCE_JDK {
      @Override
      public ImmutableBiMap<Object, Object> create(List<Entry<?, ?>> entries) {
        return ImmutableBiMap.builder().putAll(entries).buildJdkBacked();
      }
    };

    @CanIgnoreReturnValue
    public abstract ImmutableBiMap<Object, Object> create(List<Entry<?, ?>> entries);
  }

      if (map.isEmpty()) {
        return of();
      }
      return new RegularImmutableBiMap<K, V>(super.buildOrThrow());
    }

    @Override
    ImmutableBiMap<K, V> buildJdkBacked() {
      return build();
    }
  }

  public static <K, V> ImmutableBiMap<K, V> copyOf(Map<? extends K, ? extends V> map) {
    if (map instanceof ImmutableBiMap) {