while (lower <= upper) {
      int middle = (lower + upper) >>> 1;
      int c = comparator.compare(key, list.get(middle));
      if (c < 0) {
        upper = middle - 1;
      } else if (c > 0) {
        lower = middle + 1;
      } else {
        return lower
            + presentBehavior.resultIndex(
                comparator, key, list.subList(lower, upper + 1), middle - lower);
      }
    }

    while (lower <= upper) {
      int middle = (lower + upper) >>> 1;
      int c = comparator.compare(key, list.get(middle));
      if (c < 0) {
        upper = middle - 1;
      } else if (c > 0) {
        lower = middle + 1;
      } else {
        return lower
            + presentBehavior.resultIndex(
                comparator, key, list.subList(lower, upper + 1), middle - lower);
      }
    }

  private M multimap;

  protected M multimap() {
    return multimap;
  }

  /**
   * @return an array of the proper size with {@code null} as the key of the middle element.
   */
  protected Entry<K, V>[] createArrayWithNullKey() {
    Entry<K, V>[] array = createSamplesArray();
    int nullKeyLocation = getNullLocation();
    Entry<K, V> oldEntry = array[nullKeyLocation];

    for (V element : elements) {
      assertFalse("Should not contain value " + element, getMap().containsValue(element));
    }
  }

  /** @return an array of the proper size with {@code null} as the key of the middle element. */
  protected Entry<K, V>[] createArrayWithNullKey() {
    Entry<K, V>[] array = createSamplesArray();
    int nullKeyLocation = getNullLocation();
    Entry<K, V> oldEntry = array[nullKeyLocation];

    for (V element : elements) {
      assertFalse("Should not contain value " + element, getMap().containsValue(element));
    }
  }

  /** @return an array of the proper size with {@code null} as the key of the middle element. */
  protected Entry<K, V>[] createArrayWithNullKey() {
    Entry<K, V>[] array = createSamplesArray();
    int nullKeyLocation = getNullLocation();
    Entry<K, V> oldEntry = array[nullKeyLocation];

    assertEquals("Should be able to peek() at middle element", "B", peekingIterator.peek());
    assertEquals(
        "Should be able to peek() middle element multiple times", "B", peekingIterator.peek());
    assertEquals(
        "next() should still return middle element after peeking", "B", peekingIterator.next());

  }

  /** @see AbstractContainerTester#resetContainer() */
  protected void resetCollection() {
    resetContainer();
  }

  /** @return an array of the proper size with {@code null} inserted into the middle element. */
  protected E[] createArrayWithNullElement() {
    E[] array = createSamplesArray();
    array[getNullLocation()] = null;
    return array;
  }

  protected void initCollectionWithNullElement() {

    assertEquals("Should be able to peek() at middle element", "B", peekingIterator.peek());
    assertEquals(
        "Should be able to peek() middle element multiple times", "B", peekingIterator.peek());
    assertEquals(
        "next() should still return middle element after peeking", "B", peekingIterator.next());

[data-ty] {
    display: block;
    line-height: 2;
}

[data-ty]:before {
    /* Set up defaults and ensure empty lines are displayed. */
    content: '';
    display: inline-block;
    vertical-align: middle;
}

[data-ty="input"]:before,
[data-ty-prompt]:before {
    margin-right: 0.75em;
    color: var(--color-text-subtle);
}

[data-ty="input"]:before {
    content: '$';
}

<img src="/img/tutorial/extending-openapi/image03.png">

## Change the Theme

The same way you could set the syntax highlighting theme with the key `"syntaxHighlight.theme"` (notice that it has a dot in the middle):

{* ../../docs_src/configure_swagger_ui/tutorial002.py hl[3] *}

That configuration would change the syntax highlighting color theme:

<img src="/img/tutorial/extending-openapi/image04.png">