...makes the parameter optional, with a default value of `None`, the same as:


```Python
q: str | None = None
```

But the `Query` version declares it explicitly as being a query parameter.

Then, we can pass more parameters to `Query`. In this case, the `max_length` parameter that applies to strings:

```Python
q: str | None = Query(default=None, max_length=50)
```

#### Password hashing { #password-hashing }

"Hashing" means: converting some content (a password in this case) into a sequence of bytes (just a string) that looks like gibberish.

Whenever you pass exactly the same content (exactly the same password) you get exactly the same gibberish.

But you cannot convert from the gibberish back to the password.

##### Why use password hashing { #why-use-password-hashing }

///

Notice that with webhooks you are actually not declaring a *path* (like `/items/`), the text you pass there is just an **identifier** of the webhook (the name of the event), for example in `@app.webhooks.post("new-subscription")`, the webhook name is `new-subscription`.

In fact, you can return any `Response` or any sub-class of it.

/// tip

`JSONResponse` itself is a sub-class of `Response`.

///

And when you return a `Response`, **FastAPI** will pass it directly.

It won't do any data conversion with Pydantic models, it won't convert the contents to any type, etc.

    // Trigger any exception that the comparator would throw for the endpoints.
    /*
     * uncheckedCastNullableTToT is safe as long as the callers are careful to pass a "real" T
     * whenever they pass `true` for the matching `has*Bound` parameter.
     */
    if (hasLowerBound) {
      int unused =
          comparator.compare(

    return delegate().asMap();
  }

  @Override
  public void cleanUp() {
    delegate().cleanUp();
  }

  /**
   * A simplified version of {@link ForwardingCache} where subclasses can pass in an already
   * constructed {@link Cache} as the delegate.
   *
   * @since 10.0
   */
  public abstract static class SimpleForwardingCache<K, V> extends ForwardingCache<K, V> {

            zipExtractor.setMaxContentSize(100);
            zipExtractor.getText(in, null);
            fail();
        } catch (MaxLengthExceededException e) {
            // pass
        }
        zipExtractor.setMaxContentSize(-1);
    }

    public void test_getText_null() {
        try {
            zipExtractor.getText(null, null);
            fail();

  val windows: Boolean
    get() = System.getProperty("os.name", "?").startsWith("Windows")

  /**
   * Make assertions about the suppressed exceptions on this. Prefer this over making direct calls
   * so tests pass on GraalVM, where suppressed exceptions are silently discarded.
   *
   * https://github.com/oracle/graal/issues/3008
   */
  @JvmStatic

```JSON
{
  "detail": "Item not found"
}
```

/// tip

When raising an `HTTPException`, you can pass any value that can be converted to JSON as the parameter `detail`, not only `str`.

You could pass a `dict`, a `list`, etc.

They are handled automatically by **FastAPI** and converted to JSON.

///

## Add custom headers { #add-custom-headers }

    sendRequest(client, "https://valid-isrgrootx1.letsencrypt.org/robots.txt");

    try {
      sendRequest(client, "https://google.com/robots.txt");
      if (androidMorEarlier) {
        // will pass with default CAs on N or later
        fail();
      }
    } catch (SSLHandshakeException sslhe) {
      assertTrue(androidMorEarlier);
    }
  }