For large responses, returning a `Response` directly is much faster than returning a dictionary.

This is because by default, FastAPI will inspect every item inside and make sure it is serializable as JSON, using the same [JSON Compatible Encoder](../tutorial/encoder.md){.internal-link target=_blank} explained in the tutorial. This is what allows you to return **arbitrary objects**, for example database models.

   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */
  public final String to(CaseFormat format, String str) {
    checkNotNull(format);
    checkNotNull(str);
    return (format == this) ? str : convert(format, str);
  }

       * doesn't need access to the futures again, so we can just pass `null`.
       *
       * TODO(b/112550045): Allocating a single, cheaper listener is (I think) only an optimization.
       * If we make some other optimizations, this one will no longer be necessary. The optimization
       * could actually hurt in some cases, as it forces us to keep all inputs in memory until the
       * final input completes.
       */

	// The approach here is to write 8 byte sizes if needed without
	// adding a zip64 extra in the local header (too late anyway).
	var buf []byte
	if w.isZip64() {
		buf = make([]byte, dataDescriptor64Len)
	} else {
		buf = make([]byte, dataDescriptorLen)
	}
	b := writeBuf(buf)
	b.uint32(dataDescriptorSignature) // de-facto standard, required by OS X
	b.uint32(w.CRC32)
	if w.isZip64() {

	p.metricsCache.InitOnce(5*time.Second,
		cachevalue.Opts{},
		func(ctx context.Context) (DiskMetrics, error) {
			diskMetric := DiskMetrics{
				LastMinute: make(map[string]AccElem, len(p.apiLatencies)),
				APICalls:   make(map[string]uint64, len(p.apiCalls)),
			}
			for i, v := range p.apiLatencies {
				diskMetric.LastMinute[storageMetric(i).String()] = v.total()
			}
			for i := range p.apiCalls {

        // Looks like the failure case also is just reflecting back the signature we sent

        // with SMB3's negotiation validation it's no longer possible to ignore this (on the validation response)
        // make sure that validation is performed in any case
        final Smb2SigningDigest dgst = getDigest();
        if (dgst != null && !isAsync() && (getConfig().isRequireSecureNegotiate() || getErrorCode() == NtStatus.NT_STATUS_SUCCESS)) {

 *   <li>missing artifacts</li>
 *   <li>network/transfer errors</li>
 *   <li>file system errors: permissions</li>
 * </ul>
 *
 * TODO carlos: all these possible has*Exceptions and get*Exceptions methods make the clients too
 *       complex requiring a long list of checks, need to create a parent/interface/encapsulation
 *       for the types of exceptions
 */
@Deprecated
public class ArtifactResolutionResult {

### Return the error { #return-the-error }

After detecting that the credentials are incorrect, return an `HTTPException` with a status code 401 (the same returned when no credentials are provided) and add the header `WWW-Authenticate` to make the browser show the login prompt again:

 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible
// TODO(cpovirk): Make this final (but that may break Mockito spy calls).
class SameThreadScheduledExecutorService extends AbstractExecutorService
    implements ListeningScheduledExecutorService {

 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible
// TODO(cpovirk): Make this final (but that may break Mockito spy calls).
class SameThreadScheduledExecutorService extends AbstractExecutorService
    implements ListeningScheduledExecutorService {