public SampleElements<Multiset.Entry<E>> samples() {
      SampleElements<E> samples = gen.samples();
      return new SampleElements<>(
          Multisets.immutableEntry(samples.e0(), 3),
          Multisets.immutableEntry(samples.e1(), 4),
          Multisets.immutableEntry(samples.e2(), 1),
          Multisets.immutableEntry(samples.e3(), 5),
          Multisets.immutableEntry(samples.e4(), 2));
    }

    @Override

      this.entryComparator = entryComparator(emptyMap.comparator());

      // derive values for inclusive filtering from the input samples
      SampleElements<Entry<K, V>> samples = delegate.samples();
      List<Entry<K, V>> samplesList =
          asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());
      sort(samplesList, entryComparator);
      this.firstInclusive = samplesList.get(0).getKey();

                  @Override
                  protected Set<String> create(String[] elements) {
                    return intersection(
                        newHashSet(samples().e1(), samples().e3()),
                        newHashSet(samples().e2(), samples().e4()));
                  }
                })
            .named("set & disjoint")
            .withFeatures(CollectionSize.ZERO, CollectionFeature.ALLOWS_NULL_VALUES)

    public SampleElements<Multiset.Entry<E>> samples() {
      SampleElements<E> samples = gen.samples();
      return new SampleElements<>(
          Multisets.immutableEntry(samples.e0(), 3),
          Multisets.immutableEntry(samples.e1(), 4),
          Multisets.immutableEntry(samples.e2(), 1),
          Multisets.immutableEntry(samples.e3(), 5),
          Multisets.immutableEntry(samples.e4(), 2));
    }

    @Override

  @ListFeature.Require(SUPPORTS_SET)
  public void testReplaceAll() {
    getList().replaceAll(e -> samples.e3());
    expectContents(Collections.nCopies(getNumElements(), samples.e3()));
  }

  @ListFeature.Require(SUPPORTS_SET)
  public void testReplaceAll_changesSome() {
    getList().replaceAll(e -> e.equals(samples.e0()) ? samples.e3() : e);
    E[] expected = createSamplesArray();
    for (int i = 0; i < expected.length; i++) {

    SortedMultiset<E> emptyMultiset = (SortedMultiset<E>) delegate.create();
    Comparator<? super E> comparator = emptyMultiset.comparator();
    SampleElements<E> samples = delegate.samples();
    List<E> samplesList =
        asList(samples.e0(), samples.e1(), samples.e2(), samples.e3(), samples.e4());

    sort(samplesList, comparator);
    E firstInclusive = samplesList.get(0);
    E lastInclusive = samplesList.get(samplesList.size() - 1);

    }

    @Override
    public SampleElements<Entry<V, K>> samples() {
      SampleElements<Entry<K, V>> samples = generator.samples();
      return new SampleElements<>(
          reverse(samples.e0()),
          reverse(samples.e1()),
          reverse(samples.e2()),
          reverse(samples.e3()),
          reverse(samples.e4()));
    }

    private Entry<V, K> reverse(Entry<K, V> entry) {

# First Steps { #first-steps }

The simplest FastAPI file could look like this:

{* ../../docs_src/first_steps/tutorial001_py39.py *}

Copy that to a file `main.py`.

Run the live server:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:solid">main.py</u>

  <span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting development server 🚀

  }

  protected final E e0() {
    return samples.e0();
  }

  protected final E e1() {
    return samples.e1();
  }

  protected final E e2() {
    return samples.e2();
  }

  protected final E e3() {
    return samples.e3();
  }

  protected final E e4() {
    return samples.e4();
  }

    getList().replaceAll(e -> samples.e3());
    expectContents(nCopies(getNumElements(), samples.e3()));
  }

  @ListFeature.Require(SUPPORTS_SET)
  public void testReplaceAll_changesSome() {
    getList().replaceAll(e -> e.equals(samples.e0()) ? samples.e3() : e);
    E[] expected = createSamplesArray();
    for (int i = 0; i < expected.length; i++) {
      if (expected[i].equals(samples.e0())) {
        expected[i] = samples.e3();