# Templates { #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 { #install-dependencies }

  @SuppressWarnings("ThrowIfUncheckedKnownUnchecked")
  public void testThrowIfUnchecked_unchecked() {
    assertThrows(
        SomeUncheckedException.class, () -> throwIfUnchecked(new SomeUncheckedException()));
  }

  // We're testing that the method is in fact equivalent to throwing the exception directly.
  @SuppressWarnings("ThrowIfUncheckedKnownUnchecked")

Then we use the request directly, and extract the body as `bytes`. This means that FastAPI won't even try to parse the request payload as JSON.

And then in our code, we parse that YAML content directly, and then we are again using the same Pydantic model to validate the YAML content:

//// tab | Pydantic v2

# `FastAPI` class

Here's the reference information for the `FastAPI` class, with all its parameters, attributes and methods.

You can import the `FastAPI` class directly from `fastapi`:

```python
from fastapi import FastAPI
```

::: fastapi.FastAPI
    options:
        members:
            - openapi_version
            - webhooks
            - state
            - dependency_overrides
            - openapi

import java.util.Iterator;
import org.junit.Ignore;

/**
 * Tester for {@code BiMap.remove}.
 *
 * @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.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

import org.junit.Ignore;

/**
 * Common parent class for {@link ListIndexOfTester} and {@link ListLastIndexOfTester}.
 *
 * @author Chris Povirk
 */
@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.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

    /**
     * Test of constructor, of class SmbComQueryInformationResponse.
     */
    @Test
    public void testConstructor() {
        // The constructor sets the command and serverTimeZoneOffset.
        // We can't directly access serverTimeZoneOffset, but we can verify its effect.
        assertEquals(ServerMessageBlock.SMB_COM_QUERY_INFORMATION, response.command);
        assertEquals(serverTimeZoneOffset, response.getLastWriteTime());
    }

import java.util.Set;
import org.junit.Ignore;

/**
 * @author George van den Driessche
 */
@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.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python
from fastapi import Body, Cookie, File, Form, Header, Path, Query
```

::: fastapi.Query

::: fastapi.Path

::: fastapi.Body

::: fastapi.Cookie

        String result = updateLabelJob.execute();
        assertNotNull(result);
        assertTrue(result.contains("3 docs"));
        // queryBuilder field is protected, so we can't directly assert it
    }

    // Test execute() method with exception handling
    public void test_execute_withException() {
        // Register a mock that throws exception