/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first { #read-the-tutorial-first }

The next sections assume you already read the main [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

            },
            directExecutor());

    // Wait for the first task to be started in the background. It will block until we explicitly
    // stop it.
    blockingCallable.waitForStart();

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    assertThat(future2.isDone()).isFalse();

    // Stop the first task. The second task should then run.
    blockingCallable.stop();

      CertificatePinner
        .Builder()
        .add("first.com", certA1Sha256Pin, certB1Sha256Pin)
        .add("second.com", certC1Sha256Pin)
        .build()

    val expectedPins =
      listOf(
        Pin("first.com", certA1Sha256Pin),
        Pin("first.com", certB1Sha256Pin),
      )
    assertThat(certificatePinner.findMatchingPins("first.com")).isEqualTo(expectedPins)
  }

```Python
if "johndoe" == "stanleyjobson" and "love123" == "swordfish":
    ...
```

$(function() {
  $('input[type="text"],select,textarea', ".login-box,section.content")
    .first()
    .focus();
  $(".form-group .has-error")
    .first()
    .next("input,select,textarea")
    .focus();

  $("section.content input").keypress(function(e) {
    var $submitButton;
    if (e.which === 13) {
      $submitButton = $("input#submit, button#submit");
      if ($submitButton.length > 0) {
        $submitButton[0].submit();
      }

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first { #read-the-tutorial-first }

You could still use most of the features in **FastAPI** with the knowledge from the main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank}.

   *
   * @param first the first array of elements to concatenate
   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] concat(
      T[] first, T[] second, Class<@NonNull T> type) {

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

It declares an optional query parameter `q` as a `str`, and then it just returns it.

    Converter<StringWrapper, Long> converter = first.andThen(STR_TO_LONG);

    assertEquals(LONG_VAL, converter.convert(new StringWrapper(STR_VAL)));
    assertEquals(STR_VAL, converter.reverse().convert(LONG_VAL).value);

    assertEquals("StringWrapper.andThen(string2long)", converter.toString());

    new EqualsTester()
        .addEqualityGroup(first.andThen(STR_TO_LONG), first.andThen(STR_TO_LONG))
        .testEquals();
  }

	}

	if u, err := gorm.G[User](DB).Select("name").Where("name = ?", user.Name).First(ctx); err != nil {
		t.Fatalf("failed to find user, got error: %v", err)
	} else if u.Name != user.Name || u.Age != 0 {
		t.Errorf("found invalid user, got %v, expect %v", u, user)
	}

	if u, err := gorm.G[User](DB).Omit("name").Where("name = ?", user.Name).First(ctx); err != nil {
		t.Fatalf("failed to find user, got error: %v", err)