It will be generated only once, and then the same cached schema will be used for the next requests.

{* ../../docs_src/extending_openapi/tutorial001.py hl[13:14,25:26] *}

### Override the method { #override-the-method }

Now you can replace the `.openapi()` method with your new function.

{* ../../docs_src/extending_openapi/tutorial001.py hl[29] *}

### Check it { #check-it }

And then **FastAPI** will call that override instead of the original dependency.

{* ../../docs_src/dependency_testing/tutorial001_an_py310.py hl[26:27,30] *}

/// tip

You can set a dependency override for a dependency used anywhere in your **FastAPI** application.

            (byte) 49, (byte) 41, (byte) 33, (byte) 25, (byte) 17, (byte) 9, (byte) 1, (byte) 58, (byte) 50, (byte) 42, (byte) 34,
            (byte) 26, (byte) 18, (byte) 10, (byte) 2, (byte) 59, (byte) 51, (byte) 43, (byte) 35, (byte) 62, (byte) 54, (byte) 46,
            (byte) 38, (byte) 30, (byte) 22, (byte) 14, (byte) 6, (byte) 61, (byte) 53, (byte) 45, (byte) 37, (byte) 29, (byte) 21,

            if (i % 100 < 50) {
                data[i] = (byte) 'A';
            } else if (i % 100 < 75) {
                data[i] = (byte) 'B';
            } else {
                data[i] = (byte) (i % 26 + 'a');
            }
        }

        return data;
    }

  url: https://github.com/hasansezertasan
- login: alv2017
  count: 26
  avatarUrl: https://avatars.githubusercontent.com/u/31544722?v=4
  url: https://github.com/alv2017
- login: dbanty
  count: 26
  avatarUrl: https://avatars.githubusercontent.com/u/43723790?u=9d726785d08e50b1e1cd96505800c8ea8405bce2&v=4
  url: https://github.com/dbanty
- login: wshayes

## Custom `APIRoute` class in a router { #custom-apiroute-class-in-a-router }

You can also set the `route_class` parameter of an `APIRouter`:

{* ../../docs_src/custom_request_and_route/tutorial003.py hl[26] *}

In this example, the *path operations* under the `router` will use the custom `TimedRoute` class, and will have an extra `X-Response-Time` header in the response with the time it took to generate the response:

	github.com/json-iterator/go v1.1.12
	github.com/klauspost/compress v1.18.0
	github.com/klauspost/cpuid/v2 v2.2.10
	github.com/klauspost/filepathx v1.1.1
	github.com/klauspost/pgzip v1.2.6
	github.com/klauspost/readahead v1.4.0
	github.com/klauspost/reedsolomon v1.12.4
	github.com/lib/pq v1.10.9
	github.com/lithammer/shortuuid/v4 v4.2.0
	github.com/miekg/dns v1.1.65
	github.com/minio/cli v1.24.2

		{"☺☻☹", "日a本b語ç", "27 ☺☻☹=日a本b語ç\n", true},
		{"xhello", "\x00world", "17 xhello=\x00world\n", true},
		{"path", "null\x00", "", false},
		{"null\x00", "value", "", false},
		{paxSchilyXattr + "key", "null\x00", "26 SCHILY.xattr.key=null\x00\n", true},
	}

	for _, v := range vectors {
		got, err := formatPAXRecord(v.inKey, v.inVal)
		ok := (err == nil)
		if ok != v.ok {
			if v.ok {

		25: {
			IsTruncated: false,
			Objects: []ObjectInfo{
				{Name: "Asia-maps.png"},
			},
			Prefixes: []string{"Asia/"},
		},
		// ListObjectsResult-26.
		// prefix = "new" and delimiter is set in the testCase.(testCase 58).
		26: {
			IsTruncated: false,
			Objects: []ObjectInfo{
				{Name: "newPrefix0"},
				{Name: "newPrefix1"},
			},

<div style="text-align: right; margin-right: 10%;">Kabir Khan - <strong>Microsoft</strong> <a href="https://github.com/fastapi/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div>

---

"_We adopted the **FastAPI** library to spawn a **REST** server that can be queried to obtain **predictions**. [for Ludwig]_"