}

  /**
   * A callback to be invoked each time the dispatcher becomes idle (when the number of running
   * calls returns to zero).
   *
   * Note: The time at which a [call][Call] is considered idle is different depending on whether it
   * was run [asynchronously][Call.enqueue] or [synchronously][Call.execute]. Asynchronous calls
   * become idle after the [onResponse][Callback.onResponse] or [onFailure][Callback.onFailure]

      payload.writeByte('0'.code)
    }
    serverWriter.writeMessageFrame(OPCODE_BINARY, payload.snapshot())

    // Write directly to the unbuffered sink. This ensures it will become single frame.
    assertData("827e") // 'e' == 4-byte follow-up length.
    assertData(format("%04X", payload.completeSegmentByteCount()))
    assertData(payload.readByteString())
  }

    val responseA = client.newCall(requestA).execute()

    assertThat(responseA.body.string()).isEqualTo("a")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Give the socket a chance to become stale.
    connection!!.idleAtNs -= IDLE_CONNECTION_HEALTHY_NS
    Thread.sleep(250)

    val requestB =
      Request(
        url = server.url("/"),

  }

  /**
   * Either writes this request to [sink] or measures its content length. We have one method
   * do double-duty to make sure the counting and content are consistent, particularly when it comes
   * to awkward operations like measuring the encoded length of header strings, or the
   * length-in-digits of an encoded integer.
   */
  private fun writeOrCountBytes(
    sink: BufferedSink?,
    countBytes: Boolean,

import java.security.cert.CertificateFactory
import java.security.cert.X509Certificate
import okio.Buffer
import okio.ByteString
import okio.ByteString.Companion.toByteString

/**
 * Decodes a multiline string that contains a [certificate][certificatePem] which is
 * [PEM-encoded][rfc_7468]. A typical input string looks like this:
 *
 * ```
 * -----BEGIN CERTIFICATE-----

import okhttp3.Headers
import okhttp3.Request
import okhttp3.Response
import okhttp3.Route
import okhttp3.internal.connection.RealCall
import okio.Sink
import okio.Source

/** Encodes HTTP requests and decodes HTTP responses. */
interface ExchangeCodec {
  /** The connection or CONNECT tunnel that owns this codec. */
  val carrier: Carrier

  /** Returns an output stream where the request body can be streamed. */