is not available, instead of erroring out, the dependency result will
                be `None`.

                This is useful when you want to have optional authentication.

                It is also useful when you want to have authentication that can be
                provided in one of multiple optional ways (for example, in HTTP Basic
                authentication or in an HTTP Bearer token).

  * Note that because any taints you might have created with Kubernetes 1.5 can only affect the scheduling of new pods (the `NoExecute` taint effect is introduced in 1.6), neither the master upgrade nor your running `kubectl taint` to re-create the taints will affect pods that are already running.

	tests := []struct {
		sc   string
		want bool
	}{
		{"STANDARD", true},
		{"REDUCED_REDUNDANCY", true},
		{"", false},
		{"INVALID", false},
		{"123", false},
		{"MINIO_STORAGE_CLASS_RRS", false},
		{"MINIO_STORAGE_CLASS_STANDARD", false},
	}
	for i, tt := range tests {
		if got := IsValid(tt.sc); got != tt.want {

    "version" that omits the class to avoid conflicts with the copy in Guava
    itself. The idea is:

    - If users want only ListenableFuture, they depend on listenablefuture-1.0.

    - If users want all of Guava, they depend on guava, which, as of Guava
    27.0, depends on
    listenablefuture-9999.0-empty-to-avoid-conflict-with-guava. The 9999.0-...

        just a feature that seems like a sensible addition to Guava?


        Before new features get added to Guava, we really want to be sure that it's for a use case
        that actually comes up in the real world. We want to hear the real-world use case so the
        community can discuss and debate whether this feature is actually the *best* way to address

	scanner := NewScanner(&r)
	c := 0
	for scanner.Scan() {
		c++
		if c > 1 {
			t.Error("read too many lines")
			break
		}
	}
	if got, want := scanner.Err(), ErrBadReadCount; got != want {
		t.Errorf("scanner.Err: got %v, want %v", got, want)
	}
}

// largeReader returns an invalid count that is larger than the number
// of bytes requested.
type largeReader struct{}

* installation
* activation
* update
* deactivation
* un-installation

When a plugin is installed we may want to check the license and make users agree. We may also want to unpack the given plugin in a particular location.

		err := tryParse(t, func() {
			parser.Parse()
		})

		switch {
		case err == nil:
			t.Errorf("#%d: %q: want error %q; have none", i, test.input, test.error)
		case !strings.Contains(err.Error(), test.error):
			t.Errorf("#%d: %q: want error %q; have %q", i, test.input, test.error, err)
		}
	}

For example, let's say that you want to use <a href="https://github.com/ijl/orjson" class="external-link" target="_blank">`orjson`</a>, but with some custom settings not used in the included `ORJSONResponse` class.

Let's say you want it to return indented and formatted JSON, so you want to use the orjson option `orjson.OPT_INDENT_2`.

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers { #forbid-extra-headers }

In some special use cases (probably not very common), you might want to **restrict** the headers that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/header_param_models/tutorial002_an_py310.py hl[10] *}