assertTrue(sqrtMaxLong <= LongMath.FLOOR_SQRT_MAX_LONG);
  }

  @AndroidIncompatible // slow
  @GwtIncompatible // java.math.BigInteger
  public void testMean() {
    // Odd-sized ranges have an obvious mean
    assertMean(2, 1, 3);

    assertMean(-2, -3, -1);
    assertMean(0, -1, 1);
    assertMean(1, -1, 3);
    assertMean((1L << 62) - 1, -1, Long.MAX_VALUE);

    Temporarily adopting this point of view (of the *external developer*) can help you feel like it's more obvious where to put the parameters, the Pydantic model for the body, for the response, etc. for that *external API*.

### Create a callback `APIRouter`

First create a new `APIRouter` that will contain one or more callbacks.

# Generate Clients

As **FastAPI** is based on the OpenAPI specification, you get automatic compatibility with many tools, including the automatic API docs (provided by Swagger UI).

One particular advantage that is not necessarily obvious is that you can **generate clients** (sometimes called <abbr title="Software Development Kits">**SDKs**</abbr> ) for your API, for many different **programming languages**.

## OpenAPI Client Generators

// We avoid dependency on the unicode package, but check validity of the implementation
// in the tests.
func isSpace(r rune) bool {
	if r <= '\u00FF' {
		// Obvious ASCII ones: \t through \r plus space. Plus two Latin-1 oddballs.
		switch r {
		case ' ', '\t', '\n', '\v', '\f', '\r':
			return true
		case '\u0085', '\u00A0':
			return true
		}
		return false
	}

4. Validate your changes before committing.\
Run the `./gradlew sanityCheck` task again to make sure there are no more errors.

#### Filtering changes by severity

There is a somewhat non-obvious filter present on the page that allows you to control which type of messages are displayed.

However, one interesting aspect is how these policies associate with workloads.
Istio's AuthorizationPolicy has label selectors.
However, we intentionally do not send those as part of the Workload API, in order to keep the size low.

The obvious solution to this is to put the list of selected workloads into the policy itself.
However, this means anytime a workload changes (often), we need to update the policy.

            shouldDeduplicateBuiltInSymbols = false,

            // Because the file to compile may be contained in a "common" multiplatform module, an `expect` declaration doesn't necessarily
            // have an obvious associated `actual` symbol. `shouldStubOrphanedExpectSymbols` generates stubs for such `expect` declarations.
            shouldStubOrphanedExpectSymbols = true,

        <!--
            Some tests need reflective access to the internals of these packages. It is only the
            tests themselves and not the code being tested that needs that access, though there's no
            obvious way to ensure that.

            We could consider arranging things so that only the tests we know need this would get
            the add-opens. Right now that doesn't seem worth the effort, though.
        -->

	f, err := parser.ParseFile(fset, filename, nil, parser.ParseComments)
	if err != nil {
		return nil, err
	}
	parsedFileCache[filename] = f

	return f, nil
}

// Disable before debugging non-obvious errors from the type-checker.
const usePkgCache = true

var (
	pkgCache = map[string]*apiPackage{} // map tagKey to package
	pkgTags  = map[string][]string{}    // map import dir to list of relevant tags
)

	legacyWebhook := getWebhooksFromYaml(t, legacyDefaultInjector)
	legacyRevWebhook := getWebhooksFromYaml(t, legacyRevisionInjector)

	// predicate is used to filter out "obvious" test cases, to avoid enumerating all cases
	// nolint: unparam
	predicate := func(ls LabelSet) (string, bool) {
		if ls.namespace.Get("istio-injection") == "disabled" {
			return "", true
		}