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();
  }

  /**

  fun emptyCache(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    cache.close()
    assertJournalEquals()
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)
  fun recoverFromInitializationFailure(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)

     *
     * @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")
    @CheckForNull
    E removeFromChain(E first, E entry) {
      int newCount = count;
      E newFirst = entry.getNext();
      for (E e = first; e != entry; e = e.getNext()) {

	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

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

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

    }


    /**
     * @param first
     * @param n
     * @return
     * @throws IOException
     * @throws SocketException
     * @throws InterruptedException
     */
    private SmbNegotiation negotiate2 ( Smb2NegotiateResponse first ) throws IOException, SocketException {
        int size = 0;

        int securityMode = getRequestSecurityMode(first);

        // further negotiation needed

     *
     * @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")
    @CheckForNull
    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();
  }

  /**

  Define(-1, {}, {feed1, feed2}, {feed2, feed1}, {"first", "second"});

  // Use, run, and verify
  TF_Operation* two = ScalarConst(2, host_graph_, s_);
  TF_Operation* func_feed = Placeholder(host_graph_, s_);
  TF_Operation* func_op = Use({two, func_feed});
  Run({{func_feed, Int32Tensor(3)}}, {{func_op, 0}, {func_op, 1}}, {3, 2});
  VerifyFDef(empty_, M({{"feed1"}, {"feed2"}}), M({{"first"}, {"second"}}),

              (e1, e2) -> {
                // requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);
                return comparator.compare(e1.getKey(), e2.getKey());
              });
          // requireNonNull is safe because the first `size` elements have been filled in.
          Entry<K, V> firstEntry = requireNonNull(entryArray[0]);