Since FastAPI 0.119.0, there's also partial support for Pydantic v1 from inside of Pydantic v2, to facilitate the migration to v2.

So, you could upgrade Pydantic to the latest version 2, and change the imports to use the `pydantic.v1` submodule, and in many cases it would just work.

{* ../../docs_src/pydantic_v1_in_v2/tutorial002_an_py310.py hl[2,5,15] *}

/// warning

That way, the sub-application will know to use that path prefix for the docs UI.

And the sub-application could also have its own mounted sub-applications and everything would work correctly, because FastAPI handles all these `root_path`s automatically.

    /*
     * In principle, a Multimap implementation could add e3 first before failing on the null. But
     * that seems unlikely enough to be worth complicating the test over, especially if there's any
     * chance that a permissive test could mask a bug.
     */
    expectUnchanged();
    // Be extra thorough in case internal state was corrupted by the expected null.

Now, you should be able to disconnect your WiFi, go to your docs at <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>, and reload the page.

     */
    public DisniRdmaProvider() {
        // Default constructor
    }

    private static final Logger log = LoggerFactory.getLogger(DisniRdmaProvider.class);

    // DiSNI components - these would be actual DiSNI objects in a real implementation
    private Object endpointGroup; // RdmaActiveEndpointGroup<DisniRdmaEndpoint>
    private Object endpoint; // RdmaActiveEndpoint
    private boolean initialized = false;

          // it is kind of lame that we need to construct a decoder to access this value.
          // if this is a concern we could add special cases for some known charsets (like utf8)
          // or we could avoid inputstreamreader and use the decoder api directly
          // TODO(lukes): in a real implementation we would need to handle overflow conditions
          int maxChars = (int) (size.get().intValue() * cs.newDecoder().maxCharsPerByte());

    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("I bet you didn't think Thread.interrupt could throw");
    /*
     * We need to wait for the runner to exit. It used to be that the runner would get stuck in the
     * busy loop when interrupt threw.
     *
     * While we're at it, we confirm that the interrupt happened as expected.
     */

public class ExecutionError extends Error {
  /*
   * Ideally, this class would have exposed only constructors that require a non-null cause. See
   * https://github.com/jspecify/jspecify-reference-checker/blob/61aafa4ae52594830cfc2d61c8b113009dbdb045/src/main/java/com/google/jspecify/nullness/NullSpecTransfer.java#L789
   * and https://github.com/jspecify/jspecify/issues/490.
   *

This client could be a browser with a frontend, a code from someone else, an IoT device, etc.

You could need to tell the client that:

* The client doesn't have enough privileges for that operation.
* The client doesn't have access to that resource.
* The item the client was trying to access doesn't exist.
* etc.

   *
   * <ul>
   *   <li>We could change the serialization of this class incompatibly. We have reserved the right
   *       to make such changes to our serialized forms, and we have made them before, usually
   *       without trouble. In this case, my guess is that our chosen approach is even less likely
   *       to lead to trouble than an incompatible change would be.