{* ../../docs_src/first_steps/tutorial001.py hl[1] *}

`FastAPI` is a Python class that provides all the functionality for your API.

/// note | Technical Details

`FastAPI` is a class that inherits directly from `Starlette`.

You can use all the <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> functionality with `FastAPI` too.

///

  @CollectionSize.Require(absent = ZERO)
  public void testSubList_originalListSetAffectsSubList() {
    List<E> subList = getList().subList(0, 1);
    getList().set(0, e3());
    assertEquals(
        "A set() call to a list after a sublist has been created "
            + "should be reflected in the sublist",
        singletonList(e3()),
        subList);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)

This might all sound abstract. Don't worry. You'll see all this in action in the [Tutorial - User Guide](tutorial/index.md){.internal-link target=_blank}.

The important thing is that by using standard Python types, in a single place (instead of adding more classes, decorators, etc), **FastAPI** will do a lot of the work for you.

/// info

     * null} if {@code remove()} or {@code add()} has been called more recently than either. We use
     * this to determine which stack to pop from on a call to {@code remove()} (or to pop from and
     * push to on a call to {@code set()}).
     */
    @Nullable Stack<E> stackWithLastReturnedElementAtTop = null;

    MultiExceptionListIterator(List<E> expectedElements) {

            Trans2FindFirst2Response resp = inv.getArgument(1);
            int call = nextCall[0]++;
            String[] names = batches.get(call + 1);
            FE[] res = java.util.Arrays.stream(names).map(FE::new).toArray(FE[]::new);
            setField(resp, jcifs.internal.smb1.trans.SmbComTransactionResponse.class, "results", res);
            if (call == 0) {
                // first next

    .sslSocketFactory(clientCertificates.sslSocketFactory(), clientCertificates.trustManager())
    .build();

// Connect 'em all together. Certificates are exchanged in the handshake.
Call call = client.newCall(new Request.Builder()
    .url(server.url("/"))
    .build());
Response response = call.execute();
System.out.println(response.handshake().peerPrincipal());
RecordedRequest recordedRequest = server.takeRequest();

				return
			}
			// If there *is* a claim-based provider configured, then
			// treat an unrecognized roleArn the same as no roleArn
			// at all.  This is to support clients like the AWS SDKs
			// or CLI that will not allow an AssumeRoleWithWebIdentity
			// call without a RoleARN parameter - for these cases the
			// user can supply a dummy ARN, which Minio will ignore.
			roleArn = openid.DummyRoleARN

   * Builder#addAll(Iterable)}, with all the performance implications associated with that.
   */
  public static ImmutableLongArray copyOf(Iterable<Long> values) {
    if (values instanceof Collection) {
      return copyOf((Collection<Long>) values);
    }
    return builder().addAll(values).build();
  }

  /**
   * Returns an immutable array containing all the values from {@code stream}, in order.
   *

    val pooled2 = planReusePooledConnection(connect, connect.routes)
    if (pooled2 != null) return pooled2

    return connect
  }

  /**
   * Returns the connection already attached to the call if it's eligible for a new exchange.
   *
   * If the call's connection exists and is eligible for another exchange, it is returned. If it
   * exists but cannot be used for another exchange, it is closed and this returns null.

 * Tests for {@link RequestParam} covering enum mechanics and edge cases.
 */
@ExtendWith(MockitoExtension.class)
public class RequestParamTest {

    // Happy path: values() returns all constants in declaration order
    @Test
    @DisplayName("values() returns all declared constants in order")
    void valuesContainsAllInOrder() {
        RequestParam[] values = RequestParam.values();

        assertNotNull(values, "values() must not return null");