/// note

Having a default value of any type, including `None`, makes the parameter optional (not required).

///

## Required parameters { #required-parameters }

When we don't need to declare more validations or metadata, we can make the `q` query parameter required just by not declaring a default value, like:

```Python
q: str
```

instead of:

}

// concurrently load bucket metadata to speed up loading bucket metadata.
func (sys *BucketMetadataSys) concurrentLoad(ctx context.Context, buckets []string) {
	g := errgroup.WithNErrs(len(buckets))
	bucketMetas := make([]BucketMetadata, len(buckets))
	for index := range buckets {
		g.Go(func() error {
			// Sleep and stagger to avoid blocked CPU and thundering
			// herd upon start up sequence.

   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */
  public final String to(CaseFormat format, String str) {
    checkNotNull(format);
    checkNotNull(str);
    return (format == this) ? str : convert(format, str);
  }

## Dispatch

For synchronous calls, you bring your own thread and are responsible for managing how many simultaneous requests you make. Too many simultaneous connections wastes resources; too few harms latency.

      return x.longValue();
    } else if (exponent > MAX_EXPONENT) {
      return x.signum() * POSITIVE_INFINITY;
    }

    /*
     * We need the top SIGNIFICAND_BITS + 1 bits, including the "implicit" one bit. To make rounding
     * easier, we pick out the top SIGNIFICAND_BITS + 2 bits, so we have one to help us round up or
     * down. twiceSignifFloor will contain the top SIGNIFICAND_BITS + 2 bits, and signifFloor the

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses in Nested Data Structures { #dataclasses-in-nested-data-structures }

You can also combine `dataclasses` with other type annotations to make nested data structures.

In some cases, you might still have to use Pydantic's version of `dataclasses`. For example, if you have errors with the automatically generated API documentation.

       * doesn't need access to the futures again, so we can just pass `null`.
       *
       * TODO(b/112550045): Allocating a single, cheaper listener is (I think) only an optimization.
       * If we make some other optimizations, this one will no longer be necessary. The optimization
       * could actually hurt in some cases, as it forces us to keep all inputs in memory until the
       * final input completes.
       */

* Make DaemonSet respect critical pods annotation when scheduling. ([#42028](https://github.com/kubernetes/kubernetes/pull/42028), [@janetkuo](https://github.com/janetkuo))
* Implement the update feature for DaemonSet. ([#41116](https://github.com/kubernetes/kubernetes/pull/41116), [@lukaszo](https://github.com/lukaszo))

For large responses, returning a `Response` directly is much faster than returning a dictionary.

This is because by default, FastAPI will inspect every item inside and make sure it is serializable as JSON, using the same [JSON Compatible Encoder](../tutorial/encoder.md){.internal-link target=_blank} explained in the tutorial. This is what allows you to return **arbitrary objects**, for example database models.

@GwtCompatible
@NullUnmarked
public class IntMathTest extends TestCase {
  public void testMaxSignedPowerOfTwo() {
    assertTrue(IntMath.isPowerOfTwo(IntMath.MAX_SIGNED_POWER_OF_TWO));

    // Extra work required to make GWT happy.
    long value = IntMath.MAX_SIGNED_POWER_OF_TWO * 2L;
    assertFalse(IntMath.isPowerOfTwo((int) value));
  }

  public void testCeilingPowerOfTwo() {
    for (int x : POSITIVE_INTEGER_CANDIDATES) {