type declaration was nullable to support rare cases like the body on `Response.cacheResponse`,
    `Response.networkResponse`, and `Response.priorResponse`. In such cases the body is now
    non-null, but attempts to read its content will fail.
 *  New: Kotlin-specific APIs for request tags. Kotlin language users can lookup tags with a type
    parameter only, like `request.tag<MyTagClass>()`.

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003.py hl[16,19] *}

 * Service for detecting and providing information about the operating system (OS)
 * on which the application is running.
 * <p>
 * This service provides a platform-independent way to:
 * <ul>
 * <li>Query basic OS information like name, architecture, and version</li>
 * <li>Determine the OS family (e.g., Windows, Unix, Mac)</li>
 * <li>Check if the current OS is Windows-based</li>
 * </ul>
 * <p>

* Caddy
    * Automatically handles certificates renewals ✨
* Nginx
    * With an external component like Certbot for certificate renewals
* HAProxy
    * With an external component like Certbot for certificate renewals
* Kubernetes with an Ingress Controller like Nginx
    * With an external component like cert-manager for certificate renewals
* Handled internally by a cloud provider as part of their services (read below 👇)

// constant) is one of the TBL-like instructions and one of its
// inputs does not fit into prog.Reg, so require special handling.
func IsARM64TBL(op obj.As) bool {
	switch op {
	case arm64.AVTBL, arm64.AVTBX, arm64.AVMOVQ:
		return true
	}
	return false
}

// IsARM64CASP reports whether the op (as defined by an arm64.A*
// constant) is one of the CASP-like instructions, and its 2nd

        } else {
            /*
             * MNG-4900: Hack to workaround deficiency of legacy API which makes it impossible for plugins to access the
             * global profile manager which is required to build a POM like a CLI invocation does. Failure to consider
             * the activated profiles can cause repo declarations to be lost which in turn will result in artifact

            if (inDfs && !service.equals("IPC") && request.path != null && request.path.length() > 0) {
                /* When DFS is in action all request paths are
                 * full UNC paths minus the first backslash like
                 *   \server\share\path\to\file
                 * as opposed to normally
                 *   \path\to\file
                 */
                request.flags2 = SmbConstants.FLAGS2_RESOLVE_PATHS_IN_DFS;

Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
shipped. Each file adds new lines but does not remove any.

except.txt lists features that may disappear without breaking true
compatibility.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"

            final PrimaryCipher cipher = ComponentUtil.getPrimaryCipher();
            final String[] lines = value.split("[\r\n]");
            for (final String line : lines) {
                if (StringUtil.isNotBlank(line)) {
                    final int pos = line.indexOf('=');
                    if (pos == 0) {

   *   <li>{@link #JAVA_COMPILER}, while still listed as required as of Java 15, is typically not
   *       available even under older version.
   *   <li>Any property may be cleared through APIs like {@link System#clearProperty}.
   *   <li>Unusual environments like GWT may have their own special handling of system properties.
   * </ul>
   *
   * <p>Note that {@code StandardSystemProperty} does not provide constants for more recently added