*     ImmutableSetMultimap.<Character, Character>builder()
   *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
   *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
   *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
   *         .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
   *         .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
   *         .build();
   *

   *     ImmutableListMultimap.<Character, Character>builder()
   *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
   *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
   *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
   *         .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
   *         .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
   *         .build();
   * }
   *

   *     ImmutableListMultimap.<Character, Character>builder()
   *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
   *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
   *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
   *         .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
   *         .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
   *         .build();
   * }
   *

   *     ImmutableSetMultimap.<Character, Character>builder()
   *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
   *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
   *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
   *         .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
   *         .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
   *         .build();
   *

 * methods of the delegate. For example, overriding {@link #put} alone <i>will not</i> change the
 * behavior of {@link #putAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code putAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardPutAll} method.
 *

 * methods of the delegate. For example, overriding {@link #put} alone <i>will not</i> change the
 * behavior of {@link #putAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code putAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardPutAll} method.
 *

   *
   * {@snippet :
   * static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
   *     new ImmutableMultimap.Builder<String, Integer>()
   *         .put("one", 1)
   *         .putAll("several", 1, 2, 3)
   *         .putAll("many", 1, 2, 3, 4, 5)
   *         .build();
   * }
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build

        ImmutableListMultimap.<Character, Character>builder()
            .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
            .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
            .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
            .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
            .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
            .build();

   *
   * {@snippet :
   * static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
   *     new ImmutableMultimap.Builder<String, Integer>()
   *         .put("one", 1)
   *         .putAll("several", 1, 2, 3)
   *         .putAll("many", 1, 2, 3, 4, 5)
   *         .build();
   * }
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build

   * {@code put()} or {@code putAll()}, or {@code setValue()} on its entries.
   *
   * <p>In contrast, the maps returned by {@code rowMap().get()} have the same behavior as those
   * returned by {@link #row}. Those maps may support {@code setValue()}, {@code put()}, and {@code
   * putAll()}.
   *
   * @return a map view from each row key to a secondary map from column keys to values