* This is typical for Java but atypical for HTTP/2. This is motivated by exception transparency:
 * an [IOException] that was triggered by a certain caller can be caught and handled by that caller.
 */
@Suppress("NAME_SHADOWING")
class Http2Connection internal constructor(
  builder: Builder,
) : Closeable,
  Lockable {
  // Internal state of this connection is guarded by 'lock'. No blocking operations may be