val writer = Http2Writer(Buffer(), true)
    assertFailsWith<IllegalArgumentException> {
      writer.frameHeader(0, 16777216, Http2.TYPE_DATA, FLAG_NONE)
    }.also { expected ->
      // TODO: real max is based on settings between 16384 and 16777215
      assertThat(expected.message).isEqualTo("FRAME_SIZE_ERROR length > 16384: 16777216")
    }
  }

  @Test fun ackSettingsAppliesMaxFrameSize() {