int len = sequence.length();
    int first;
    int last;

    for (first = 0; first < len; first++) {
      if (!matches(sequence.charAt(first))) {
        break;
      }
    }
    for (last = len - 1; last > first; last--) {
      if (!matches(sequence.charAt(last))) {
        break;
      }
    }

    return sequence.subSequence(first, last + 1).toString();
  }

  /**

	if err := DB.Create(&users).Error; err != nil {
		t.Fatalf("errors happened when create users: %v", err)
	}

	t.Run("First", func(t *testing.T) {
		var first User
		if err := DB.Where("name = ?", "find").First(&first).Error; err != nil {
			t.Errorf("errors happened when query first: %v", err)
		} else {
			CheckUser(t, first, users[0])
		}
	})

	t.Run("Last", func(t *testing.T) {
		var last User

     *
     * @param first the first entry of the table
     * @param entry the entry being removed from the table
     * @return the new first entry for the table
     */
    @GuardedBy("this")
    @Nullable E removeFromChain(E first, E entry) {
      int newCount = count;
      E newFirst = entry.getNext();
      for (E e = first; e != entry; e = e.getNext()) {

    int len = sequence.length();
    int first;
    int last;

    for (first = 0; first < len; first++) {
      if (!matches(sequence.charAt(first))) {
        break;
      }
    }
    for (last = len - 1; last > first; last--) {
      if (!matches(sequence.charAt(last))) {
        break;
      }
    }

    return sequence.subSequence(first, last + 1).toString();
  }

  /**

                buf.append(",\"data\":[");

                boolean first = true;
                for (final SuggestItem item : suggestResponse.getItems()) {
                    if (!first) {
                        buf.append(',');
                    }
                    first = false;

     *
     * @param first the first entry of the table
     * @param entry the entry being removed from the table
     * @return the new first entry for the table
     */
    @GuardedBy("this")
    @Nullable E removeFromChain(E first, E entry) {
      int newCount = count;
      E newFirst = entry.getNext();
      for (E e = first; e != entry; e = e.getNext()) {

   */
  public static String toString(Iterator<?> iterator) {
    StringBuilder sb = new StringBuilder().append('[');
    boolean first = true;
    while (iterator.hasNext()) {
      if (!first) {
        sb.append(", ");
      }
      first = false;
      sb.append(iterator.next());
    }
    return sb.append(']').toString();
  }

  /**

   */
  public static String toString(Iterator<?> iterator) {
    StringBuilder sb = new StringBuilder().append('[');
    boolean first = true;
    while (iterator.hasNext()) {
      if (!first) {
        sb.append(", ");
      }
      first = false;
      sb.append(iterator.next());
    }
    return sb.append(']').toString();
  }

  /**

    assertTrue(result.isEmpty());
    testProp.setProperty("first", "true");

    result = Maps.fromProperties(testProp);
    assertThat(result.get("first")).isEqualTo("true");
    assertEquals(1, result.size());
    testProp.setProperty("second", "null");

    result = Maps.fromProperties(testProp);
    assertThat(result.get("first")).isEqualTo("true");
    assertThat(result.get("second")).isEqualTo("null");

      // 1. Server reads request and dequeues first response
      // 2. Client cancels request
      // 3. Server tries to send response on the canceled stream
      // Otherwise, there is no guarantee for the sequence. For example, the server may use the
      // first mocked response to respond to the second request.
      val response = super.dispatch(request)