*
   * @throws IllegalArgumentException if duplicate keys or values are added
   */
  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
    checkEntryNotNull(k1, v1);
    checkEntryNotNull(k2, v2);
    return new RegularImmutableBiMap<K, V>(new Object[] {k1, v1, k2, v2}, 2);
  }

  /**
   * Returns an immutable map containing the given entries, in order.
   *

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
    return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2));
  }

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
    return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2, k3, v3));
  }

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {

      K k1, V v1, K k2, V v2) {
    return new Builder<K, V>(Ordering.natural()).put(k1, v1).put(k2, v2).build();
  }

  public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V> of(
      K k1, V v1, K k2, V v2, K k3, V v3) {
    return new Builder<K, V>(Ordering.natural()).put(k1, v1).put(k2, v2).put(k3, v3).build();
  }

  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
    return RegularImmutableBiMap.fromEntries(entryOf(k1, v1), entryOf(k2, v2));
  }

  /**
   * Returns an immutable map containing the given entries, in order.
   *
   * @throws IllegalArgumentException if duplicate keys or values are added
   */
  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {

                new DefaultMavenMetadataCache.CacheKey(a1, false, lr1, Collections.singletonList(rr1));
        DefaultMavenMetadataCache.CacheKey k2 =
                new DefaultMavenMetadataCache.CacheKey(a2, false, lr2, Collections.singletonList(rr2));

        assertEquals(k1.hashCode(), k2.hashCode());
    }

   *
   * @throws IllegalArgumentException if duplicate keys are provided
   */
  public static <K, V> ImmutableMap<K, V> of(K k1, V v1, K k2, V v2) {
    checkEntryNotNull(k1, v1);
    checkEntryNotNull(k2, v2);
    return RegularImmutableMap.create(2, new Object[] {k1, v1, k2, v2});
  }

  /**
   * Returns an immutable map containing the given entries, in order.
   *

   */
  public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V> of(
      K k1, V v1, K k2, V v2) {
    return fromEntries(entryOf(k1, v1), entryOf(k2, v2));
  }

  /**
   * Returns an immutable sorted map containing the given entries, sorted by the natural ordering of
   * their keys.
   *

                if (LANG_KEY.equals(k1)) {
                    return -1;
                }
                final String k2 = o2.getKey();
                if (LANG_KEY.equals(k2)) {
                    return -1;
                }
                return k1.compareTo(k2);
            });
            return new LinkedHashSet<>(list);
        }
        return parent.entrySet();
    }

   */
  public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V> of(
      K k1, V v1, K k2, V v2) {
    return fromEntries(entryOf(k1, v1), entryOf(k2, v2));
  }

  /**
   * Returns an immutable sorted map containing the given entries, sorted by the natural ordering of
   * their keys.
   *

    ImmutableListMultimap.Builder<K, V> builder = ImmutableListMultimap.builder();
    builder.put(k1, v1);
    builder.put(k2, v2);
    return builder.build();
  }

  /** Returns an immutable multimap containing the given entries, in order. */
  public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {