* Adds a header with [name] and [value]. Prefer this method for multiply-valued
     * headers like "Cookie".
     *
     * Note that for some headers including `Content-Length` and `Content-Encoding`,
     * OkHttp may replace [value] with a header derived from the request body.
     */
    open fun addHeader(
      name: String,
      value: String,
    ) = commonAddHeader(name, value)

      } catch (e: IOException) {
        failConnection(e)
      }
    }
  }

  fun writePing(
    reply: Boolean,
    payload1: Int,
    payload2: Int,
  ) {
    try {
      writer.ping(reply, payload1, payload2)
    } catch (e: IOException) {
      failConnection(e)
    }
  }

  /** For testing: sends a ping and waits for a pong. */

     * parameters, and as it turns out Firefox and Chrome actually do rather different things, and
     * both say in their comments that they're not really sure what the right approach is. We go
     * with Chrome's behavior (which also experimentally seems to match what IE does), but if you

  private var receivedPingCount = 0

  /** Total number of pongs received by this web socket. */
  private var receivedPongCount = 0

  /** True if we have sent a ping that is still awaiting a reply. */
  private var awaitingPong = false

  init {
    require("GET" == originalRequest.method) {
      "Request must be GET: ${originalRequest.method}"
    }

_2021-11-22_

 *  Fix: Change `Headers.toString()` to redact authorization and cookie headers.
 *  Fix: Don't do DNS to get the hostname for `RecordedRequest.requestUrl`. This was doing a DNS
    lookup for the local hostname, but we really just wanted the `Host` header.
 *  Fix: Don't crash with a `InaccessibleObjectException` when detecting the platform trust manager
    on Java 17+.
 *  Fix: Don't crash if a cookie's value is a lone double quote character.

        throw errorException ?: StreamResetException(errorCode!!)
      }
      throw IllegalStateException("too early; can't read the trailers yet")
    }
  }

  /**
   * Sends a reply to an incoming stream.
   *
   * @param outFinished true to eagerly finish the output stream to send data to the remote peer.
   *     Corresponds to `FLAG_FIN`.

      }

    private fun readClientRandom(param: String): String? {
      val matchResult = randomRegex.find(param)

      return if (matchResult != null) {
        matchResult.groupValues[1].replace(" ", "")
      } else {
        null
      }
    }

    override fun secureConnectStart(call: Call) {
      // Register to capture "Produced ClientHello handshake message".

          }
        }
      }
    ```

### Customizing Trusted Certificates ([.kt][CustomTrustKotlin], [.java][CustomTrustJava])

The full code sample shows how to replace the host platform’s certificate authorities with your own set. As above, **do not use custom certificates without the blessing of your server’s TLS administrator!**

=== ":material-language-kotlin: Kotlin"
    ```kotlin

import okio.BufferedSource
import okio.Sink
import okio.Timeout
import okio.buffer
import okio.sink
import okio.source

/**
 * A scriptable web server. Callers supply canned responses and the server replays them upon request
 * in sequence.
 */
@ExperimentalOkHttpApi
class MockWebServer : Closeable {
  private val taskRunnerBackend =
    TaskRunner.RealBackend(

      }
    }
    while (!buffer.exhausted()) {
      var publicSuffix = buffer.readUtf8LineStrict()
      if (publicSuffix.contains("*")) {
        // A wildcard rule, let's replace the wildcard with a value.
        publicSuffix = publicSuffix.replace("\\*".toRegex(), "square")
      }
      assertThat(publicSuffixDatabase.getEffectiveTldPlusOne(publicSuffix)).isNull()
      val test = "foobar.$publicSuffix"