assertThrows(NullPointerException.class, () -> ImmutableList.of("a", null, "b"));
  }

  public void testCreation_generic() {
    List<String> a = ImmutableList.of("a");
    // only verify that there is no compile warning
    ImmutableList<List<String>> unused = ImmutableList.of(a, a);
  }

  public void testCreation_arrayOfArray() {
    String[] array = new String[] {"a"};
    List<String[]> list = ImmutableList.<String[]>of(array);

   * @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
   *     is not a power of two
   */
  @SuppressWarnings("fallthrough")
  // TODO(kevinb): remove after this warning is disabled globally
  public static int log2(long x, RoundingMode mode) {
    checkPositive("x", x);
    switch (mode) {
      case UNNECESSARY:
        checkRoundingUnnecessary(isPowerOfTwo(x));

    testSortDescending(new char[] {'A', '1', 'B', '2'}, 1, 3, new char[] {'A', 'B', '1', '2'});
  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Character> none = Arrays.<Character>asList();
    assertThat(Chars.toArray(none)).isEqualTo(EMPTY);

    List<Character> one = Arrays.asList((char) 1);
    assertThat(Chars.toArray(one)).isEqualTo(ARRAY1);

その後の`open("./somefile.txt")`は「コンテキストマネージャ」と呼ばれるオブジェクトを作成します。

`with`ブロックが終了すると、例外があったとしてもファイルを確かに閉じます。

`yield`を依存関係を作成すると、**FastAPI** は内部的にそれをコンテキストマネージャに変換し、他の関連ツールと組み合わせます。

### `yield`を持つ依存関係でのコンテキストマネージャの使用

/// warning | 注意

これは多かれ少なかれ、「高度な」発想です。

**FastAPI** を使い始めたばかりの方は、とりあえずスキップした方がよいかもしれません。

///

   * iterable}. The iterator's {@code hasNext()} method returns {@code true} until {@code iterable}
   * is empty.
   *
   * <p><b>Warning:</b> Typical uses of the resulting iterator may produce an infinite loop. You
   * should use an explicit {@code break} or be certain that you will eventually remove all the
   * elements.
   */

									title="<la:message key="labels.development_mode_warning" />"
								><a class="nav-link active" href="${installationLink}" target="_olh"><em
										class="fa fa-exclamation-triangle text-warning"
									></a></li>
							</c:if>
							<c:choose>
								<c:when test="${!empty username && username != 'guest'}">
									<li class="nav-item">
										<div class="dropdown">

   *
   * <p>Note however that if your escaper does not escape characters in the supplementary range, you
   * should either continue to validate the correctness of any surrogate characters encountered or
   * provide a clear warning to users that your escaper does not validate its input.
   *
   * <p>See {@link com.google.common.net.PercentEscaper} for an example.
   *
   * @param csq a sequence of characters

   *
   * <p>Note however that if your escaper does not escape characters in the supplementary range, you
   * should either continue to validate the correctness of any surrogate characters encountered or
   * provide a clear warning to users that your escaper does not validate its input.
   *
   * <p>See {@link com.google.common.net.PercentEscaper} for an example.
   *
   * @param csq a sequence of characters

        }

        try {
            "".getBytes(DEFAULT_OEM_ENCODING);
        } catch (final UnsupportedEncodingException uee) {
            if (LogStream.level >= 2) {
                log.println("WARNING: The default OEM encoding " + DEFAULT_OEM_ENCODING
                        + " does not appear to be supported by this JRE. The default encoding will be US-ASCII.");
            }
            DEFAULT_OEM_ENCODING = "US-ASCII";

<img src="/img/tutorial/behind-a-proxy/image02.png">

一切正常。 ✔️

这是因为 FastAPI 在 OpenAPI 里使用 `root_path` 提供的 URL 创建默认 `server`。

## 附加的服务器

/// warning | 警告

此用例较难，可以跳过。

///

默认情况下，**FastAPI** 使用 `root_path` 的链接在 OpenAPI 概图中创建 `server`。

但也可以使用其它备选 `servers`，例如，需要同一个 API 文档与 staging 和生产环境交互。