if (c.isLowSurrogate() || !low.isLowSurrogate()) {
              '?'.code
            } else {
              i++
              0x010000 + (c.code and 0x03ff shl 10 or (low.code and 0x03ff))
            }
          }

          else -> c.code
        }
      i++
    }
    return result
  }

  private val Int.punycodeDigit: Int
    get() =

  }

  @Test fun streamIdHasReservedBit() {
    val writer = Http2Writer(Buffer(), true)
    assertFailsWith<IllegalArgumentException> {
      var streamId = 3
      streamId = streamId or (1L shl 31).toInt() // set reserved bit
      writer.frameHeader(streamId, Http2.INITIAL_MAX_FRAME_SIZE, Http2.TYPE_DATA, FLAG_NONE)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("reserved bit set: -2147483645")