val writeObjectBean = SerializableWriteObjectBean(Pair(writeReplaceBean, writeReplaceBean))
            pairOf(writeObjectBean)
        }) { (first, second) ->
            assertThat(
                first,
                sameInstance(second)
            )
            val decodedPair = first.value as Pair<*, *>
            assertThat(
                decodedPair.first,

        return right;
    }

    public static <L, R> Pair<L, R> of(@Nullable L left, @Nullable R right) {
        return new Pair<L, R>(left, right);
    }

    public <T> Pair<T, Pair<L, R>> pushLeft(T t) {
        return of(t, this);
    }

    public <T> Pair<Pair<L, R>, T> pushRight(T t) {
        return of(this, t);
    }

    public <T> Pair<Pair<T, L>, R> nestLeft(T t) {
        return of(of(t, left), right);

     */
    public static <T1, T2> Pair<T1, T2> pair(final T1 first, final T2 second) {
        return new Pair<>(first, second);
    }

    /**
     * インスタンスを構築します。
     */
    public Pair() {
    }

    /**
     * インスタンスを構築します。
     *
     * @param first
     *            1番目の値
     * @param second
     *            2番目の値
     */
    public Pair(final T1 first, final T2 second) {

package http

// A mapping is a collection of key-value pairs where the keys are unique.
// A zero mapping is empty and ready to use.
// A mapping tries to pick a representation that makes [mapping.find] most efficient.
type mapping[K comparable, V any] struct {
	s []entry[K, V] // for few pairs
	m map[K]V       // for many pairs
}

type entry[K comparable, V any] struct {
	key   K
	value V
}

  // Modification Operations

  /**
   * Stores a key-value pair in this multimap.
   *
   * <p>Some multimap implementations allow duplicate key-value pairs, in which case {@code put}
   * always adds a new key-value pair and increases the multimap size by 1. Other implementations
   * prohibit duplicates, and storing a key-value pair that's already in the multimap has no effect.
   *

  // Modification Operations

  /**
   * Stores a key-value pair in this multimap.
   *
   * <p>Some multimap implementations allow duplicate key-value pairs, in which case {@code put}
   * always adds a new key-value pair and increases the multimap size by 1. Other implementations
   * prohibit duplicates, and storing a key-value pair that's already in the multimap has no effect.
   *

  /**
   * Returns the population covariance of the values. The count must be non-zero.
   *
   * <p>This is guaranteed to return zero if the dataset contains a single pair of finite values. It
   * is not guaranteed to return zero when the dataset consists of the same pair of values multiple
   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *

  /**
   * Returns the population covariance of the values. The count must be non-zero.
   *
   * <p>This is guaranteed to return zero if the dataset contains a single pair of finite values. It
   * is not guaranteed to return zero when the dataset consists of the same pair of values multiple
   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *

        final Map<String, List<String>> paramListMap = new HashMap<>();
        final String[] pairs = queryString.split("&");
        try {
            for (final String pair : pairs) {
                final int pos = pair.indexOf('=');
                if (pos >= 0) {
                    final String key = urlCodec.decode(pair.substring(0, pos), enc);
                    List<String> list = paramListMap.get(key);

    assertThat(headers["e"]).isNull()
  }

  @Test fun iteratorOperator() {
    val headers = headersOf("a", "b", "c", "d")

    val pairs = mutableListOf<Pair<String, String>>()
    for ((name, value) in headers) {
      pairs += name to value
    }

    assertThat(pairs).containsExactly("a" to "b", "c" to "d")
  }

  @Test fun builderGetOperator() {
    val builder = Headers.Builder()
    builder.add("a", "b")