* This is particularly important for **security**, we'll see more of that below.

## `response_model` Parameter

There are some cases where you need or want to return some data that is not exactly what the type declares.

     * configuration). This is useful when you want to force the user to use common POM elements rather than plugin
     * configurations, as in the case where you want to use the artifact's final name as a parameter. In this case, you
     * want the user to modify <code>&lt;build&gt;&lt;finalName/&gt;&lt;/build&gt;</code> rather than specifying a value

	if domain := S3.String(); domain != Domain {
		t.Errorf("S3's string method returns wrong domain: got '%s' - want '%s'", domain, Domain)
	}
}

func TestSSECString(t *testing.T) {
	const Domain = "SSE-C"
	if domain := SSEC.String(); domain != Domain {
		t.Errorf("SSEC's string method returns wrong domain: got '%s' - want '%s'", domain, Domain)
	}
}

var ssecUnsealObjectKeyTests = []struct {
	Headers        http.Header

In some cases, you may want to override the logic used by the `Request` and `APIRoute` classes.

In particular, this may be a good alternative to logic in a middleware.

For example, if you want to read or manipulate the request body before it is processed by your application.

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

	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 {

  /**
   * No-op null-pointer test for {@link LongAdder} to override the {@link PackageSanityTests}
   * version, which checks package-private methods that we don't want to have to annotate as {@code
   * Nullable} because we don't want diffs from jsr166e.
   */
  public void testNulls() {}

  public void testOverflows() {
    LongAdder longAdder = new LongAdder();
    longAdder.add(Long.MAX_VALUE);

# Development - Contributing

First, you might want to see the basic ways to [help FastAPI and get help](help-fastapi.md){.internal-link target=_blank}.

## Developing

If you already cloned the <a href="https://github.com/fastapi/fastapi" class="external-link" target="_blank">fastapi repository</a> and you want to deep dive in the code, here are some guidelines to set up your environment.

### Virtual environment

But you are not restricted to using some specific data model, class or type.

Do you want to have an `id` and `email` and not have any `username` in your model? Sure. You can use these same tools.

Do you want to just have a `str`? Or just a `dict`? Or a database class model instance directly? It all works the same way.

    "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