But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

But as it's a common use case, it is provided by **FastAPI** directly, just to make it easier.

///

### Use the form data

/// tip

 */
@Deprecated(since = "4.0.0")
public interface ModelInterpolator {

    /**
     * Interpolates expressions in the specified model. Note that implementations are free to either interpolate the
     * provided model directly or to create a clone of the model and interpolate the clone. Callers should always use
     * the returned model and must not rely on the input model being updated.
     *

* **Uvicorn**:
    * Will have the best performance, as it doesn't have much extra code apart from the server itself.

 * FILE_WRITE_DATA</tt>) and the target file has the following security
 * descriptor ACEs:
 * <pre>
 * Allow WNET\alice     0x001200A9  Direct
 * Allow Administrators 0x001F01FF  Inherited
 * Allow SYSTEM         0x001F01FF  Inherited
 * </pre>
 * the access check would fail because the direct ACE has an access mask
 * of <tt>0x001200A9</tt> which doesn't have the

import okhttp3.internal.platform.Platform

/**
 * Modern reflection based SocketAdapter for Conscrypt class SSLSockets.
 *
 * This is used directly for providers where class name is known e.g. the Google Play Provider
 * but we can't compile directly against it, or in fact reliably know if it is registered and
 * on classpath.
 */

import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#putIfAbsent}. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

# Templates

You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and install `jinja2`:

<div class="termy">

		Free:   uint64(s.F_bsize) * uint64(s.F_bavail),
		Files:  uint64(s.F_files),
		Ffree:  uint64(s.F_ffree),
		FSType: getFSType(s.F_fstypename[:]),
	}
	if info.Free > info.Total {
		return info, fmt.Errorf("detected free space (%d) > total drive space (%d), fs corruption at (%s). please run 'fsck'", info.Free, info.Total, path)
	}
	info.Used = info.Total - info.Free
	return info, nil
}

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

5.2. If You initiate litigation against any entity by asserting a patent
     infringement claim (excluding declaratory judgment actions, counter-claims,
     and cross-claims) alleging that a Contributor Version directly or
     indirectly infringes any patent, then the rights granted to You by any and
     all Contributors for the Covered Software under Section 2.1 of this License
     shall terminate.