Iterable<Character> result = Traverser.forGraph(graph).breadthFirst('a');

    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'b');

    // Iterate again to see if calculation is done again
    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'a', 'b', 'b');
  }

  @Test

    Iterable<Character> result = Traverser.forGraph(graph).breadthFirst('a');

    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'b');

    // Iterate again to see if calculation is done again
    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'a', 'b', 'b');
  }

  @Test

    } catch (UnsupportedOperationException expected) {
    }
  }

  /**
   * Verifies that an Iterator is unmodifiable.
   *
   * <p>This test only works with iterators that iterate over a finite set.
   */
  public static void assertIteratorIsUnmodifiable(Iterator<?> iterator) {
    while (iterator.hasNext()) {
      iterator.next();
      try {
        iterator.remove();

    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
   * multimap, save that if all values associated with a key are removed and then the key is added

    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
   * multimap, save that if all values associated with a key are removed and then the key is added

비동기 제너레이터 또는 일반 제너레이터/이터레이터를 받아 응답 본문을 스트리밍 합니다.

{* ../../docs_src/custom_response/tutorial007.py hl[2,14] *}

#### 파일과 같은 객체를 사용한 `StreamingResponse`

파일과 같은 객체(예: `open()`으로 반환된 객체)가 있는 경우, 해당 파일과 같은 객체를 반복(iterate)하는 제너레이터 함수를 만들 수 있습니다.

이 방식으로, 파일 전체를 메모리에 먼저 읽어들일 필요 없이, 제너레이터 함수를 `StreamingResponse`에 전달하여 반환할 수 있습니다.

이 방식은 클라우드 스토리지, 비디오 처리 등의 다양한 라이브러리와 함께 사용할 수 있습니다.

 *
 * <p>The collections returned by {@code keySet}, {@code keys}, and {@code asMap} iterate through
 * the keys in the order they were first added to the multimap. Similarly, {@code get}, {@code
 * removeAll}, and {@code replaceValues} return collections that iterate through the values in the
 * order they were added. The collections generated by {@code entries} and {@code values} iterate
 * across the key-value mappings in the order they were added to the multimap.
 *

   * convenient.
   *
   * <p>By default, a {@code Builder} will generate bimaps that iterate over entries in the order
   * they were inserted into the builder. For example, in the above example, {@code
   * WORD_TO_INT.entrySet()} is guaranteed to iterate over the entries in the order {@code "one"=1,
   * "two"=2, "three"=3}, and {@code keySet()} and {@code values()} respect the same order. If you

2. By using a `with` block, we make sure that the file-like object is closed after the generator function is done. So, after it finishes sending the response.
3. This `yield from` tells the function to iterate over that thing named `file_like`. And then, for each part iterated, yield that part as coming from this generator function (`iterfile`).

    So, it is a generator function that transfers the "generating" work to something else internally.

        i += 4;

        assert i == body.length;
        return body;
    }

    /**
     * Build a CREATE response body with a single, unrecognized create context.
     * The parser should iterate it but produce an empty contexts array.
     */
    private static byte[] buildCreateBodyWithContext(byte[] fileId, int contextStartOffsetFromHeader) {
        // Base body part size (up to and including CreateContextsLength)