**FastAPI** provides several tools to help you deal with **Security** easily, rapidly, in a standard way, without having to study and learn all the security specifications.

But first, let's check some small concepts.

## In a hurry? { #in-a-hurry }

    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md){.internal-link target=_blank}.

/// 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

  private static final ImmutableSet<String> NO_PS =
      ImmutableSet.of("www", "foo.ihopethiswillneverbeapublicsuffix", "x.y.z");

  /**
   * Having a public suffix is equivalent to having a registry suffix, because all registry suffixes
   * are public suffixes, and all public suffixes have registry suffixes.
   */
  private static final ImmutableSet<String> NO_RS = NO_PS;

```

...this would work:

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

And of course, you can define some parameters as required, some as having a default value, and some entirely optional:

{* ../../docs_src/query_params/tutorial006_py310.py hl[8] *}

In this case, there are 3 query parameters:

* `needy`, a required `str`.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

Because this code is executed before the application **starts** taking requests, and right after it **finishes** handling requests, it covers the whole application **lifespan** (the word "lifespan" will be important in a second 😉).

      val rule = publicSuffixList.bytes.binarySearch(domainLabelsUtf8Bytes, i)
      if (rule != null) {
        exactMatch = rule
        break
      }
    }

    // In theory, wildcard rules are not restricted to having the wildcard in the leftmost position.
    // In practice, wildcards are always in the leftmost position. For now, this implementation
    // cheats and does not attempt every possible permutation. Instead, it only considers wildcards

        assertTrue(entry.isExpired());
        assertTrue(entry.needsRefresh());
    }

    @Test
    public void testNeedsRefresh() {
        assertFalse(entry.needsRefresh());

        // Mark as having changes
        entry.updateChild("file1.txt", 1024L, 1000L, false, 0x20, 500L, 800L);
        assertTrue(entry.hasChanges());
        assertTrue(entry.needsRefresh());

        // Mark as complete (clears changes)

   * @since 12.0 (present as {@code compare} since 2.0)
   */
  public abstract ComparisonChain compareFalseFirst(boolean left, boolean right);

  /**
   * Ends this comparison chain and returns its result: a value having the same sign as the first
   * nonzero comparison result in the chain, or zero if every result was zero.
   */
  public abstract int result();

## Conflict Resolution

Conflicts in an open source project can take many forms, from someone having a bad day and using harsh and hurtful language in the issue queue, to more serious instances such as sexist/racist statements or threats of violence, and everything in between.

   * this initiates service shutdown and returns immediately. If the service is {@linkplain
   * State#NEW new}, it is {@linkplain State#TERMINATED terminated} without having been started nor
   * stopped. If the service has already been stopped, this method returns immediately without
   * taking action.
   *
   * @return this
   * @since 15.0
   */
  @CanIgnoreReturnValue
  Service stopAsync();

  /**