crawlingInfoHelper.documentExpires = currentTime + 5000;

        // For this test, we'll focus on the documentExpires fallback logic
        // since creating full CrawlingConfig mocks would require implementing many abstract methods
        Date result = crawlingInfoHelper.documentExpires != null ? new Date(crawlingInfoHelper.documentExpires) : null;
        assertNotNull(result);

# SQL (Relational) Databases { #sql-relational-databases }

**FastAPI** doesn't require you to use a SQL (relational) database. But you can use **any database** that you want.

Here we'll see an example using [SQLModel](https://sqlmodel.tiangolo.com/).

**SQLModel** is built on top of [SQLAlchemy](https://www.sqlalchemy.org/) and Pydantic. It was made by the same author of **FastAPI** to be the perfect match for FastAPI applications that need to use **SQL databases**.

Available JDKs on your machine are automatically detected and wired for the various compile and test tasks.
Some tests require multiple JDKs to be installed on your computer, be aware of this if you make changes related to anything toolchains related.

   * reconstructed using public factory methods. This ensures that the implementation types remain
   * as implementation details.
   *
   * <p>Since the bimap is immutable, ImmutableBiMap doesn't require special logic for keeping the
   * bimap and its inverse in sync during serialization, the way AbstractBiMap does.
   */
  @J2ktIncompatible // serialization

    }
    
    private void fallbackToTcp(RdmaConnection connection) {
        log.info("Falling back to TCP transport");
        // Switch transport to TCP
        // This would require transport factory modification
    }
}
```

## 10. Security Considerations

### 10.1 RDMA Security
```java
public class RdmaSecurityManager {

        SimpleProblemCollector result = validate("invalid-aggregator-packaging-pom.xml");

        assertViolations(result, 0, 1, 0);

        assertTrue(result.getErrors().get(0).contains("Aggregator projects require 'pom' as packaging."));
    }

    @Test
    void testMissingDependencyArtifactId() throws Exception {
        SimpleProblemCollector result = validate("missing-dependency-artifactId-pom.xml");

    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md).

/// tip

Having `dependencies` in the `APIRouter` can be used, for example, to require authentication for a whole group of *path operations*. Even if the dependencies are not added individually to each one of them.

///

/// check

   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would
   * require its own suppression, since it is also unsound. toArray(T[]) is just a mess from a
   * nullness perspective. The signature below at least has the virtue of being relatively simple.
   */
  @SuppressWarnings("nullness")

      return true;
    }
    // This falls into the undirected A->B->A case. The Graph interface does not support parallel
    // edges, so this traversal would require reusing the undirected AB edge.
    return false;
  }

  /**
   * Returns the transitive closure of {@code graph}. The transitive closure of a graph {@code G} is

 * supertype of `Function<A, B>` turns out to be massively more useful to callers in practice: They
 * want their output to be non-null in operations like `stream.map(myConverter)`, and we can
 * guarantee that as long as we also require the input type to be non-null[*] (which is a
 * requirement that existing callers already fulfill).
 *
 * Disclaimer: Part of the reason that callers are so well adapted to `Function<A, B>` may be that