assertNotNull(instance1);
        assertNotNull(instance2);
        // The second setInstance replaces the first, so they should not be the same
        assertNotSame(instance1, instance2);
        // Getting instance again should return the same as instance2
        assertSame(instance2, LogStream.getInstance());
    }

    @Test
    void testLogStreamInheritsFromPrintStream() {

You can easily use the same Pydantic settings to configure your generated OpenAPI and the docs UIs.

For example:

{* ../../docs_src/conditional_openapi/tutorial001_py39.py hl[6,11] *}

Here we declare the setting `openapi_url` with the same default of `"/openapi.json"`.

And then we use it when creating the `FastAPI` app.

{* ../../docs_src/openapi_webhooks/tutorial001_py39.py hl[9:13,36:53] *}

The webhooks that you define will end up in the **OpenAPI** schema and the automatic **docs UI**.

/// info

You can use the same dependency *functions* you use normally.

### Dependency requirements { #dependency-requirements }

They can declare request requirements (like headers) or other sub-dependencies:

{* ../../docs_src/dependencies/tutorial006_an_py39.py hl[8,13] *}

### Raise exceptions { #raise-exceptions }

These dependencies can `raise` exceptions, the same as normal dependencies:

/**
 * A bimap (or "bidirectional map") is a map that preserves the uniqueness of its values as well as
 * that of its keys. This constraint enables bimaps to support an "inverse view", which is another
 * bimap containing the same entries as this bimap but with reversed keys and values.
 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableBiMap}
 *   <li>{@link HashBiMap}
 *   <li>{@link EnumBiMap}

  }

  // Node/edge sets are the same, but node/edge connections differ due to edge type.
  @Test
  public void equivalent_directedVsUndirected() {
    graph.putEdge(N1, N2);

    MutableGraph<Integer> g2 = createGraph(oppositeType(edgeType));
    g2.putEdge(N1, N2);

    assertThat(graph).isNotEqualTo(g2);
  }

  // Node/edge sets and node/edge connections are the same, but directedness differs.
  @Test

// The iterator yields the same subslices that would be returned by [Split](s, sep),
// but without constructing a new slice containing the subslices.
// It returns a single-use iterator.
func SplitSeq(s, sep []byte) iter.Seq[[]byte] {
	return splitSeq(s, sep, 0)
}

// SplitAfterSeq returns an iterator over subslices of s split after each instance of sep.

        // Assert
        assertArrayEquals(h2, h1, "nTOWFv1 should return NT hash");
        assertEquals(16, h1.length, "NT hash length is 16 bytes");
    }

    @Test
    @DisplayName("nTOWFv2: overloads produce same result and domain affects key")
    void testNTOWFv2_overloadsAndDomainSensitivity() {
        // Arrange
        String domain = "Domain";
        String user = "User";
        String password = "password";

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

For example, if you have a function:

```Python
@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"
```

your program could execute like this:

```mermaid
sequenceDiagram

participant code as Code