## [Responses](https://square.github.io/okhttp/5.x/okhttp/okhttp3/-response/)

The response answers the request with a code (like 200 for success or 404 for not found), headers, and its own optional body.

## Rewriting Requests

import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Basic implementation of the {@link SetMultimap} interface. It's a wrapper around {@link
 * AbstractMapBasedMultimap} that converts the returned collections into {@code Sets}. The {@link
 * #createCollection} method must return a {@code Set}.
 *
 * @author Jared Levy
 */
@GwtCompatible

import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Basic implementation of the {@link SetMultimap} interface. It's a wrapper around {@link
 * AbstractMapBasedMultimap} that converts the returned collections into {@code Sets}. The {@link
 * #createCollection} method must return a {@code Set}.
 *
 * @author Jared Levy
 */
@GwtCompatible

public interface BiMap<K extends @Nullable Object, V extends @Nullable Object> extends Map<K, V> {
  // Modification Operations

  /**
   * {@inheritDoc}
   *
   * @throws IllegalArgumentException if the given value is already bound to a different key in this
   *     bimap. The bimap will remain unmodified in this event. To avoid this exception, call {@link
   *     #forcePut} instead.
   */
  @CanIgnoreReturnValue
  @Override

     * throw on a regular basis here.
     *
     * @param host the hostname to resolve
     * @param tc the CIFS context
     * @return resolved name, null if not found
     */
    public synchronized NbtAddress getByName(final String host, final CIFSContext tc) {
        return getByName(new Name(tc.getConfig(), host, 0x20, null), tc);
    }

                KerberosKey serverKey = keysByAlgo.get(encType.getValue().intValue());
                if (keysByAlgo.isEmpty() || serverKey == null) {
                    throw new PACDecodingException("Kerberos key not found for eType " + encType.getValue());
                }

                try {
                    byte[] decrypted = KerberosEncData.decrypt(crypt, serverKey, serverKey.getKeyType());

            throw new IllegalArgumentException(
                    "Repository list contains duplicate entries. Each repository must be unique based on its ID and URL. "
                            + "Found " + repositories.size() + " repositories but only " + set.size()
                            + " unique entries.");
        }
        if (repositories.stream().anyMatch(Objects::isNull)) {

* **`400 - 499`** stehen für „Client error“-Responses („Client-Fehler“). Diese sind die zweithäufigsten, die Sie vermutlich verwenden werden.
    * Ein Beispiel ist `404`, für eine „Not Found“-Response („Nicht gefunden“).
    * Für allgemeine Fehler beim Client können Sie einfach `400` verwenden.

/// info

Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

But if you have a bunch of dataclasses laying around, this is a nice trick to use them to power a web API using FastAPI. 🤓

///

## Dataclasses in `response_model` { #dataclasses-in-response-model }

You can also use `dataclasses` in the `response_model` parameter:

* **`400 - 499`** – статус-коды, сообщающие о клиентской ошибке. Это ещё одна наиболее часто используемая категория.
    * Пример – код `404` для статуса "Not Found".
    * Для общих ошибок со стороны клиента можно просто использовать код `400`.