internal val streams = mutableMapOf<Int, Http2Stream>()
  internal val connectionName: String = builder.connectionName
  internal var lastGoodStreamId = 0

  /** http://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-5.1.1 */
  internal var nextStreamId = if (builder.client) 3 else 2

  private var isShutdown = false

  /** For scheduling everything asynchronous. */

import okio.Buffer
import okio.BufferedSource
import okio.ByteString
import okio.Source
import okio.buffer

/**
 * Read and write HPACK v10.
 *
 * http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12
 *
 * This implementation uses an array for the dynamic table and a list for indexed entries. Dynamic

 * > using either the HTTP GET or POST method and the other requirements
 * > of this section.  The DNS API server defines the URI used by the
 * > request through the use of a URI Template.
 *
 * [doh_spec]: https://tools.ietf.org/html/draft-ietf-doh-dns-over-https-13
 */
class DnsOverHttps internal constructor(
  @get:JvmName("client") val client: OkHttpClient,
  @get:JvmName("url") val url: HttpUrl,
  @get:JvmName("includeIPv6") val includeIPv6: Boolean,

        sslSocket.enabledProtocols.intersect(tlsVersionsAsString, naturalOrder())
      } else {
        sslSocket.enabledProtocols
      }

    // In accordance with https://tools.ietf.org/html/draft-ietf-tls-downgrade-scsv-00 the SCSV
    // cipher is added to signal that a protocol fallback has taken place.
    val supportedCipherSuites = sslSocket.supportedCipherSuites
    val indexOfFallbackScsv =