*/
  public MapJoiner withKeyValueSeparator(String keyValueSeparator) {
    return new MapJoiner(this, keyValueSeparator);
  }

  /**
   * An object that joins map entries in the same manner as {@code Joiner} joins iterables and
   * arrays. Like {@code Joiner}, it is thread-safe and immutable.
   *
   * <p>In addition to operating on {@code Map} instances, {@code MapJoiner} can operate on {@code

 *
 * <p>Unlike {@code java.util.HashSet}, iteration is only proportional to the actual {@code size()},
 * which is optimal, and <i>not</i> the size of the internal hashtable, which could be much larger
 * than {@code size()}. Furthermore, this structure only depends on a fixed number of arrays; {@code
 * add(x)} operations <i>do not</i> create objects for the garbage collector to deal with, and for

    reverse(array, newFirstIndex, toIndex);
    reverse(array, fromIndex, toIndex);
  }

  /**
   * Returns an array containing each value of {@code collection}, converted to a {@code short}
   * value in the manner of {@link Number#shortValue}.
   *
   * <p>Elements are copied from the argument collection as if by {@code collection.toArray()}.
   * Calling this method is as thread-safe as calling that method.
   *

    reverse(array, newFirstIndex, toIndex);
    reverse(array, fromIndex, toIndex);
  }

  /**
   * Returns an array containing each value of {@code collection}, converted to a {@code long} value
   * in the manner of {@link Number#longValue}.
   *
   * <p>Elements are copied from the argument collection as if by {@code collection.toArray()}.
   * Calling this method is as thread-safe as calling that method.
   *

 *
 * <p>Unlike {@code java.util.HashMap}, iteration is only proportional to the actual {@code size()},
 * which is optimal, and <i>not</i> the size of the internal hashtable, which could be much larger
 * than {@code size()}. Furthermore, this structure places significantly reduced load on the garbage
 * collector by only using a constant number of internal objects.
 *