final AuthenticationResult result = future.get(acquisitionTimeout, TimeUnit.MILLISECONDS);
            if (result == null) {
                throw new SsoLoginException("authentication result was null");
            }
            return result;
        } catch (final Exception e) {
            throw new SsoLoginException("Failed to get a token.", e);
        } finally {
            if (service != null) {

#### MIT License ####

The following files were ported to Go from C files of libyaml, and thus
are still covered by their original MIT license, with the additional
copyright staring in 2011 when the project was ported over:

    apic.go emitterc.go parserc.go readerc.go scannerc.go
    writerc.go yamlh.go yamlprivateh.go

Copyright (c) 2006-2010 Kirill Simonov
Copyright (c) 2006-2011 Kirill Simonov

   * the information of these hash codes in an ordered fashion. That is, whenever two equal hash
   * codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
   * was computed from the <i>same</i> input hash codes in the <i>same</i> order.
   *
   * @throws IllegalArgumentException if {@code hashCodes} is empty, or the hash codes do not all
   *     have the same bit length
   */

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

    conn := manager.Connection(host)
	
    payload := []byte("request")
    response, err := conn.SingleRequest(ctx, grid.HandlerDiskInfo, payload)
```

If the error type is `*RemoteErr`, then the error was returned by the remote server. Otherwise it is a local error.

Context timeouts are propagated, and a default timeout of 1 minute is added if none is specified.

There is no cancellation propagation for single payload requests.

	if spaces {
		return "", nil, ErrInvalidEncryptionKeyID
	}
	return strings.TrimPrefix(keyID, ARNPrefix), ctx, nil
}

// IsEncrypted returns true if the object metadata indicates
// that the object was uploaded using SSE-KMS.
func (ssekms) IsEncrypted(metadata map[string]string) bool {
	if _, ok := metadata[MetaSealedKeyKMS]; ok {
		return true
	}
	return false
}

		v, ok = r.Form[xhttp.AmzContentSha256]
		if !ok {
			v, ok = r.Header[xhttp.AmzContentSha256]
		}
	} else {
		v, ok = r.Header[xhttp.AmzContentSha256]
	}

	// Skip if no header was set.
	if !ok {
		return true
	}

	// If x-amz-content-sha256 is set and the value is not
	// 'UNSIGNED-PAYLOAD' we should validate the content sha256.
	switch v[0] {
	case unsignedPayload, unsignedPayloadTrailer:

        failure_count += 1
        elem_name = 'failure'
      else:
        error_count += 1
        elem_name = 'error'
      if command:
        failure_msg = (f'\nThe command was:\n\n'
                       f'{command}\n\n')
      else:
        failure_msg = ('\nCouldn\'t parse a bazel command '
                       'matching the invocation, inside the log. '

        break
      }
    }

    return result.readUtf8()
  }

  /**
   * Converts a single label from Punycode to Unicode.
   *
   * @return true if the range of [string] from [pos] to [limit] was valid and decoded successfully.
   *     Otherwise, the decode failed.
   */
  private fun decodeLabel(
    string: String,
    pos: Int,
    limit: Int,
    result: Buffer,
  ): Boolean {

Blocking APIs are convenient because you get top-to-bottom procedural code without indirection. Network calls work like regular method calls: ask for data and it is returned. If the request fails, you get a stacktrace right where the call was made.

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols