u, err := url.Parse(apiEndpoint)
		if err != nil {
			continue
		}
		if host == "" && isIPv6(u.Hostname()) {
			// Skip all IPv6 endpoints
			continue
		}
		if u.Port() == "80" && u.Scheme == "http" || u.Port() == "443" && u.Scheme == "https" {
			u.Host = u.Hostname()
		}
		newAPIEndpoints[i] = u.String()
	}
	return newAPIEndpoints
}

 *
 *  * A DNS lookup failed
 *  * The configuration is incapable of carrying the request, such as when the client is configured
 *    to use `H2_PRIOR_KNOWLEDGE` but the URL's scheme is `https:`.
 *  * Preemptive proxy authentication failed.
 *
 * Planning failures are not necessarily fatal. For example, even if we can't DNS lookup the first
 * proxy in a list, looking up a subsequent one may succeed.
 */

{* ../../docs_src/security/tutorial005_an_py310.py hl[5,9,13,47,65,106,108:116,122:125,129:135,140,156] *}

Now let's review those changes step by step.

## OAuth2 Security scheme

The first change is that now we are declaring the OAuth2 security scheme with two available scopes, `me` and `items`.

The `scopes` parameter receives a `dict` with each scope as a key and the description as the value:

    description: Optional[str] = None
    url: AnyUrl


class Schema(BaseModelWithConfig):
    # Ref: JSON Schema 2020-12: https://json-schema.org/draft/2020-12/json-schema-core.html#name-the-json-schema-core-vocabu
    # Core Vocabulary
    schema_: Optional[str] = Field(default=None, alias="$schema")
    vocabulary: Optional[str] = Field(default=None, alias="$vocabulary")

// isServerResolvable - checks if the endpoint is resolvable
// by sending a naked HTTP request with liveness checks.
func isServerResolvable(endpoint Endpoint, timeout time.Duration) error {
	serverURL := &url.URL{
		Scheme: endpoint.Scheme,
		Host:   endpoint.Host,
		Path:   pathJoin(healthCheckPathPrefix, healthCheckLivenessPath),
	}

	httpClient := &http.Client{
		Transport: globalInternodeTransport,
	}

	stsEndpointURL, err := url.Parse(stsEndpoint)
	if err != nil {
		log.Fatalf("Error parsing sts endpoint: %v", err)
	}
	copts := &minio.Options{
		Creds:  li,
		Secure: stsEndpointURL.Scheme == "https",
	}
	minioClient, err := minio.New(stsEndpointURL.Host, copts)
	if err != nil {
		log.Fatalf("Error initializing client: ", err)
	}

	// Use minIO Client object normally like the regular client.

			if err != nil {
				logger.Fatal(err, "Invalid MINIO_BROWSER_REDIRECT_URL value in environment variable")
			}
			// Look for if URL has invalid values and return error.
			if !((u.Scheme == "http" || u.Scheme == "https") &&
				u.Opaque == "" &&
				!u.ForceQuery && u.RawQuery == "" && u.Fragment == "") {

 * containers to incorporate similar functionality.
 * <p>
 * How NTLMSSP is used in conjunction with HTTP and MSIE clients is
 * described in an <A HREF="http://www.innovation.ch/java/ntlm.html">NTLM
 * Authentication Scheme for HTTP</A>.
 * <p>
 * Also, read <a
 * href="../../../ntlmhttpauth.html">jCIFS NTLM HTTP Authentication and
 * the Network Explorer Servlet</a> related information.
 */
@Deprecated

interface PushObserver {
  /**
   * Describes the request that the server intends to push a response for.
   *
   * @param streamId server-initiated stream ID: an even number.
   * @param requestHeaders minimally includes `:method`, `:scheme`, `:authority`,
   * and `:path`.
   */
  fun onRequest(
    streamId: Int,
    requestHeaders: List<Header>,
  ): Boolean

  /**

    val request = server.takeRequest()
    assertThat(request.requestLine).isEqualTo(
      "GET /a/deep/path?key=foo%20bar HTTP/1.1",
    )
    val requestUrl = request.requestUrl
    assertThat(requestUrl!!.scheme).isEqualTo("http")
    assertThat(requestUrl.host).isEqualTo(server.hostName)
    assertThat(requestUrl.port).isEqualTo(server.port)
    assertThat(requestUrl.encodedPath).isEqualTo("/a/deep/path")