}

  /**
   * Returns a hash table for the specified keys and values, and ensures that neither keys nor
   * values are null. This method may update {@code alternatingKeysAndValues} if there are duplicate
   * keys. If so, the return value will indicate how many entries are still valid, and will also
   * include a {@link Builder.DuplicateKey} in case duplicate keys are not allowed now or will not

  @DoNotCall("Always throws UnsupportedOperationException")
  public final ImmutableList<V> replaceValues(K key, Iterable<? extends V> values) {
    throw new UnsupportedOperationException();
  }

  /**
   * @serialData number of distinct keys, and then for each distinct key: the key, the number of
   *     values for that key, and the key's values
   */
  @GwtIncompatible
  @J2ktIncompatible

    assertEmpty(multimap().entries());
    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    multimap().clear();
    assertCleared();
  }

   * provided key-value mapping, this method has no effect.
   *
   * <p>Note that a successful call to this method could cause the size of the bimap to increase by
   * one, stay the same, or even decrease by one.
   *
   * <p><b>Warning:</b> If an existing entry with this value is removed, the key for that entry is
   * discarded and not returned.
   *

        // No matching host header
        String key = virtualHostHelper.getVirtualHostKey();
        assertEquals("", key);

        // Matching host header
        request.addHeader("Host", "example.com");
        key = virtualHostHelper.getVirtualHostKey();
        assertEquals("", key); // Still empty due to caching

        // Test caching by calling again - should return cached value
        key = virtualHostHelper.getVirtualHostKey();

 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs
 * quickly, since the row key is provided. However, {@code column(columnKey).size()} takes longer,

 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs
 * quickly, since the row key is provided. However, {@code column(columnKey).size()} takes longer,

   * remove()}. Otherwise, all optional operations are supported. Null row keys, columns keys, and
   * values are not supported.
   *
   * <p>Lookups by row key are often faster than lookups by column key, because the data is stored
   * in a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still
   * runs quickly, since the row key is provided. However, {@code column(columnKey).size()} takes

    }

    assertEquals(values.size(), multimap().get(key).size());
    assertEquals(values.size() > 0, multimap().containsKey(key));
    assertEquals(values.size() > 0, multimap().keySet().contains(key));
    assertEquals(values.size() > 0, multimap().keys().contains(key));
  }

     */
    public BeanMap() {
    }

    @Override
    public Object get(final Object key) {
        if (!containsKey(key)) {
            throw new IllegalKeyOfBeanMapException(key, this);
        }
        return super.get(key);
    }