Поля `example` как такового не существует в стандартах **JSON Schema**. В последних версиях JSON-схемы определено поле <a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a>, но OpenAPI 3.0.3 основан на более старой версии JSON-схемы, которая не имела поля `examples`.

<img src="https://fastapi.tiangolo.com/img/tutorial/body-fields/image01.png">

## 技術詳細

`example` と `examples`について...

JSON Schemaの最新バージョンでは<a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a>というフィールドを定義していますが、OpenAPIは`examples`を持たない古いバージョンのJSON Schemaをベースにしています。

 *
 * ## Preemptive Authentication
 *
 * To make HTTPS calls using an HTTP proxy server OkHttp must first negotiate a connection with
 * the proxy. This proxy connection is called a "TLS Tunnel" and is specified by
 * [RFC 2817][1]. The HTTP CONNECT request that creates this tunnel connection is special: it
 * does not participate in any [interceptors][Interceptor] or [event listeners][EventListener]. It

### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

Since version 5.0, `OkHttpClient` supports fast fallback, which is our implementation of Happy Eyeballs [RFC 6555](https://datatracker.ietf.org/doc/html/rfc6555).

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

    val mediaType = parse("text/plain; charset=utf-8; charset=utf-16")
    assertEquals("UTF-8", mediaType.charsetName())
  }

  /**
   * This is invalid according to RFC 822. But it's what Chrome does and it avoids a potentially
   * unpleasant IllegalCharsetNameException.
   */
  @Test fun testCharsetNameIsSingleQuoted() {
    val mediaType = parse("text/plain;charset='utf-8'")

O **JSON Schema** na verdade não tem um campo `example` nos padrões. Versões recentes do JSON Schema definem um campo <a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a>, mas o OpenAPI 3.0.3 é baseado numa versão mais antiga do JSON Schema que não tinha `examples`.

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3

import java.nio.charset.Charset

/**
 * An [RFC 2045][rfc_2045] Media Type, appropriate to describe the content type of an HTTP request
 * or response body.
 *
 * [rfc_2045]: http://tools.ietf.org/html/rfc2045
 */
class MediaType internal constructor(

        int outlen = 5;
        byte[] expanded = PacMac.expandNFold(data, outlen);
        assertNotNull(expanded);
        assertEquals(outlen, expanded.length);

        // Test vectors from RFC 3961 Appendix A.1
        // 64-fold("012345")
        verifyNfold("012345", 8,
                new byte[] { (byte) 0xbe, (byte) 0x07, (byte) 0x26, (byte) 0x31, (byte) 0x27, (byte) 0x6b, (byte) 0x19, (byte) 0x55 });

import okhttp3.internal.toCanonicalHost
import okhttp3.internal.trimSubstring
import okhttp3.internal.unmodifiable
import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

/**
 * An [RFC 6265](http://tools.ietf.org/html/rfc6265) Cookie.
 *
 * This class doesn't support additional attributes on cookies, like
 * [Chromium's Priority=HIGH extension][chromium_extension].
 *

            System.arraycopy(block, 0, dk, n, len);
            n += len;
            enc = block;
        }
        return dk;
    }

    /**
     * Performs n-fold expansion of data as specified in RFC 3961.
     * This operation is used in Kerberos key derivation to expand or compress
     * input data to a specific output length.
     *
     * @param data the input data to expand