* IllegalArgumentException} if passed a {@code fromKey} less than an earlier {@code fromKey}.
   * However, this method doesn't throw an exception in that situation, but instead keeps the
   * original {@code fromKey}. Similarly, this method keeps the original {@code toKey}, instead of
   * throwing an exception, if passed a {@code toKey} greater than an earlier {@code toKey}.
   */
  @Override

   *   <li>If a constructor or factory method takes a parameter whose type is interface, a dynamic
   *       proxy will be passed to the method. It's possible that the method body expects an
   *       instance method of the passed-in proxy to be of a certain value yet the proxy isn't aware
   *       of the assumption, in which case the equality check before and after serialization will
   *       fail.

 *     class (such as {@link #named(String)}) return this type, so that Builder methods of more
 *     derived classes can be chained onto them without casting.
 * @param <G> The type of the generator to be passed to testers in the generated test suite. An
 *     instance of G should somehow provide an instance of the class under test, plus any other
 *     information required to parameterize the test.
 * @see FeatureSpecificTestSuiteBuilder

 *     class (such as {@link #named(String)}) return this type, so that Builder methods of more
 *     derived classes can be chained onto them without casting.
 * @param <G> The type of the generator to be passed to testers in the generated test suite. An
 *     instance of G should somehow provide an instance of the class under test, plus any other
 *     information required to parameterize the test.
 * @see FeatureSpecificTestSuiteBuilder

app = FastAPI()

app.add_middleware(UnicornMiddleware, some_config="rainbow")
```

`app.add_middleware()` receives a middleware class as the first argument and any additional arguments to be passed to the middleware.

## Integrated middlewares { #integrated-middlewares }

**FastAPI** includes several middlewares for common use cases, we'll see next how to use them.

/// note | Technical Details

There are several parameters that you can pass to your *path operation decorator* to configure it.

/// warning

Notice that these parameters are passed directly to the *path operation decorator*, not to your *path operation function*.

///

## Response Status Code { #response-status-code }

You can define the (HTTP) `status_code` to be used in the response of your *path operation*.

You can pass directly the `int` code, like `404`.

        assertTrue(deleteJobLogCalled[0]);
        assertTrue(deleteUserInfoCalled[0]);
        assertTrue(updateJobLogStatusCalled[0]);

        // Assert correct parameters were passed - verify that time passed is greater than 0
        assertTrue(crawlingInfoDeletedBeforeTime[0] > 0);
        assertEquals(30, searchLogDeletedDays[0]);
        assertEquals(14, jobLogDeletedDays[0]);

                        authId: oauth2.auth.name,
                        source: "auth",
                        level: "warning",
                        message: "Authorization may be unsafe, passed state was changed in server. The passed state wasn't returned from auth server."
                    });
                }

                if (qp.code) {
                    delete oauth2.state;

### JSON Performance { #json-performance }

		if err != nil && testCase.shouldPass {
			t.Errorf("Test %d: %s: Expected to pass, but failed with: <ERROR> %s", i+1, instanceType, err.Error())
		}
		if err == nil && !testCase.shouldPass {
			t.Errorf("Test %d: %s: Expected to fail with <ERROR> \"%s\", but passed instead", i+1, instanceType, testCase.err.Error())
		}
		// Failed as expected, but does it fail for the expected reason.