/// info | Technical Details

**FastAPI** will know that it can use the class `OAuth2PasswordBearer` (declared in a dependency) to define the security scheme in OpenAPI because it inherits from `fastapi.security.oauth2.OAuth2`, which in turn inherits from `fastapi.security.base.SecurityBase`.

All the security utilities that integrate with OpenAPI (and the automatic API docs) inherit from `SecurityBase`, that's how **FastAPI** can know how to integrate them in OpenAPI.

             * 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
             * resolution failures, in particular when using the enhanced local repo which guards access to local files
             * based on the configured remote repos.
             */

		ipList.Add(addr)
	}

	return ipList, err
}

// sortIPs - sort ips based on higher octets.
// The logic to sort by last octet is implemented to
// prefer CIDRs with higher octets, this in-turn skips the
// localhost/loopback address to be not preferred as the
// first ip on the list. Subsequently this list helps us print
// a user friendly message with appropriate values.
func sortIPs(ipList []string) []string {

				"X-Amz-Date": now.Format(iso8601Format),
			},
			region:   "",
			expected: ErrUnsignedHeaders,
		},
	}

	// Run each test case individually.
	for i, testCase := range testCases {
		// Turn the map[string]string into map[string][]string, because Go.
		query := url.Values{}
		for key, value := range testCase.queryParams {
			query.Set(key, value)
		}

		// Create a request to use.

Now we are going to update our dependencies.

We want to get the `current_user` *only* if this user is active.

So, we create an additional dependency `get_current_active_user` that in turn uses `get_current_user` as a dependency.

Both of these dependencies will just return an HTTP error if the user doesn't exist, or if is inactive.

* etc.

## Simple and Powerful { #simple-and-powerful }

Although the hierarchical dependency injection system is very simple to define and use, it's still very powerful.

You can define dependencies that in turn can define dependencies themselves.

    assertThat(pool.connectionCount()).isEqualTo(1)

    // All other connections created will expire sooner
    routePlanner.defaultConnectionIdleAtNanos = expireSooner

    // Turn it into an http/2 connection that supports 5 concurrent streams
    // which can satisfy a larger policy
    val connection = routePlanner.plans.first().connection
    val http2Connection = connectHttp2(peer, connection, 5)

 * [HTTP Public Key Pinning (HPKP)][rfc_7469] or SHA-1 base64 hashes as in Chromium's
 * [static certificates][static_certificates].
 *
 * ## Setting up Certificate Pinning
 *
 * The easiest way to pin a host is turn on pinning with a broken configuration and read the
 * expected configuration when the connection fails. Be sure to do this on a trusted network, and
 * without man-in-the-middle tools like [Charles][charles] or [Fiddler][fiddler].
 *

				}
				for i+1 < len(printed) && (printed[i+1] == ' ' || printed[i+1] == '\t') {
					i++
				}
				continue
			}
			buf = append(buf, c)
		}

		f := strings.Fields(string(buf))

		// Turn relative (PC) into absolute (PC) automatically,
		// so that most branch instructions don't need comments
		// giving the absolute form.
		if len(f) > 0 && strings.Contains(printed, "(PC)") {
			index := len(f) - 1

   *       for every closeable object this step creates in order to capture it for later closing.
   *   <li>Return a {@code ClosingFuture}. To turn a {@link ListenableFuture} into a {@code
   *       ClosingFuture} call {@link #from(ListenableFuture)}.
   *   <li>In case this step doesn't create new closeables, you can adapt an API that returns a