*/
    boolean is(String propertyKey);

    /**
     * Get the value for the key 'lasta_di.smart.deploy.mode'. <br>
     * The value is, e.g. warm <br>
     * comment: The mode of Lasta Di's smart-deploy, should be cool in production (e.g. hot, cool, warm)
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

In this case, the function parameter `q` will be optional, and will be `None` by default.

/// check

Also notice that **FastAPI** is smart enough to notice that the path parameter `item_id` is a path parameter and `q` is not, so, it's a query parameter.

///

## Query parameter type conversion { #query-parameter-type-conversion }

```Python hl_lines="3  5-6"
{
    "name": "Baz",
    "description": None,
    "price": 50.2,
    "tax": 10.5,
    "tags": []
}
```

FastAPI is smart enough (actually, Pydantic is smart enough) to realize that, even though `description`, `tax`, and `tags` have the same values as the defaults, they were set explicitly (instead of taken from the defaults).

            lifespan=lifespan,
        )
        if prefix:
            assert prefix.startswith("/"), "A path prefix must start with '/'"
            assert not prefix.endswith("/"), (
                "A path prefix must not end with '/', as the routes will start with '/'"
            )
        self.prefix = prefix
        self.tags: list[Union[str, Enum]] = tags or []

            Doc(
                """
                Configuration passed to Pydantic to define if the response data should
                exclude fields set to `None`.

                This is much simpler (less smart) than `response_model_exclude_unset`
                and `response_model_exclude_defaults`. You probably want to use one of
                those two instead of this one, as those allow returning `None` values

				"application/vnd.shana.informed.interchange",
				"application/vnd.shana.informed.package",
				"application/vnd.simtech-mindmapper",
				"application/vnd.smaf",
				"application/vnd.smart.teacher",
				"application/vnd.software602.filler.form+xml",
				"application/vnd.software602.filler.form-xml-zip",
				"application/vnd.solent.sdkm+xml",
				"application/vnd.spotfire.dxp",

        final DefaultIntervalController controller = new DefaultIntervalController();
        controller.setDelayMillisAfterProcessing(0L);

        final long start = System.nanoTime();
        controller.delayAfterProcessing();
        final long elapsed = (System.nanoTime() - start) / 1000000;

        assertTrue("No delay expected", elapsed < 50); // Should be nearly instant
    }

    /**

   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableLongArray(long[] array) {
    this(array, 0, array.length);
  }

  private ImmutableLongArray(long[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
  }

   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableIntArray(int[] array) {
    this(array, 0, array.length);
  }

  private ImmutableIntArray(int[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
  }

        }

        try {
            final long start = System.currentTimeMillis();
            final SuggestWriterResult result = suggestWriter.write(client, settings, index, array, true);
            return new SuggestIndexResponse(items.length, items.length, result.getFailures(), System.currentTimeMillis() - start);
        } catch (final Exception e) {