if (closed) throw IOException("closed")

    // Disable the timeout to read the first byte of a new frame.
    val b0: Int
    val timeoutBefore = source.timeout().timeoutNanos()
    source.timeout().clearTimeout()
    try {
      b0 = source.readByte() and 0xff
    } finally {
      source.timeout().timeout(timeoutBefore, TimeUnit.NANOSECONDS)
    }

    opcode = b0 and B0_MASK_OPCODE

   * connections.
   */
  private fun detachTimeout(timeout: ForwardingTimeout) {
    val oldDelegate = timeout.delegate
    timeout.setDelegate(Timeout.NONE)
    oldDelegate.clearDeadline()
    oldDelegate.clearTimeout()
  }

  /**
   * The response body from a CONNECT should be empty, but if it is not then we should consume it
   * before proceeding.
   */
  fun skipConnectBody(response: Response) {

					},

					// func clearTimeoutEvent(id int32)
					"runtime.clearTimeoutEvent": (sp) => {
						sp >>>= 0;
						const id = this.mem.getInt32(sp + 8, true);
						clearTimeout(this._scheduledTimeouts.get(id));
						this._scheduledTimeouts.delete(id);
					},

					// func getRandomData(r []byte)
					"runtime.getRandomData": (sp) => {
						sp >>>= 0;