# Advanced Security { #advanced-security }

## Additional Features { #additional-features }

There are some extra features to handle security apart from the ones covered in the [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

     */
    @Nonnull
    <T> Optional<T> lookupOptional(Class<T> type, String name);

    /**
     * Performs a collection lookup for given typed components.
     *
     * @param type The component type.
     * @return The list of components. The list may be empty if no components found.
     * @param <T> The component type.

Asynchronous code just means that the language 💬 has a way to tell the computer / program 🤖 that at some point in the code, it 🤖 will have to wait for *something else* to finish somewhere else. Let's say that *something else* is called "slow-file" 📝.

So, during that time, the computer can go and do some other work, while "slow-file" 📝 finishes.

    File jarFile = new File("base/some.jar");
    Manifest manifest = manifestClasspath("file:the^file.jar");
    assertThat(ClassPath.getClassPathFromManifest(jarFile, manifest))
        .containsExactly(fullpath("base/the^file.jar"));
  }

  public void testGetClassPathFromManifest_relativeDirectory() throws IOException {
    File jarFile = new File("base/some.jar");

     */
    @Nonnull
    default String message() {
        return "";
    }

    /**
     * Some CI systems may allow running jobs in "debug" (or some equivalent) mode.
     */
    default boolean isVerbose() {
        return false;
    }

    * A "token" is just a string with some content that we can use later to verify this user.
    * Normally, a token is set to expire after some time.
        * So, the user will have to log in again at some point later.
        * And if the token is stolen, the risk is less. It is not like a permanent key that will work forever (in most of the cases).

            executor.shutdown();

            // Some requests should be rejected due to backpressure
            assertTrue(rejectedCount.get() > 0, "Some requests should be rejected by backpressure");
            assertTrue(successCount.get() > 0, "Some requests should succeed");
            assertEquals(5, rejectedCount.get() + successCount.get(), "Total should be 5");

### Certificate Renewal { #certificate-renewal }

At some point in the future, each certificate would **expire** (about 3 months after acquiring it).

And then, there would be another program (in some cases it's another program, in some cases it could be the same TLS Termination Proxy) that would talk to Let's Encrypt, and renew the certificate(s).

extend-exclude = [".git/", "docs/", "CREDITS", "go.mod", "go.sum"]
ignore-hidden = false

[default]
extend-ignore-re = [
    "Patrick Collison",
    "Copyright 2014 Unknwon",
    "[0-9A-Za-z/+=]{64}",
    "ZXJuZXQxDjAMBgNVBA-some-junk-Q4wDAYDVQQLEwVNaW5pbzEOMAwGA1UEAxMF",
    "eyJmb28iOiJiYXIifQ",
    "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.*",
    "MIIDBTCCAe2gAwIBAgIQWHw7h.*",
    'http\.Header\{"X-Amz-Server-Side-Encryptio":',

{* ../../docs_src/dependencies/tutorial008_an_py39.py hl[18:19,26:27] *}

The same way, you could have some dependencies with `yield` and some other dependencies with `return`, and have some of those depend on some of the others.

And you could have a single dependency that requires several other dependencies with `yield`, etc.

You can have any combinations of dependencies that you want.