server.processNextFrame()
    // Not closed until close reply is received.
    assertThat(client.closed).isFalse()

    // Manually write an invalid masked close frame.
    server.sink.write("888760b420bb635c68de0cd84f".decodeHex()).emit()
    client.processNextFrame() // Detects error, disconnects immediately since close already sent.
    client.webSocket!!.finishReader()
    assertThat(client.closed).isTrue()

    clientWriter.writeClose(1001, null)
    assertData("888260b420bb635d")
  }

  @Test fun clientCloseWithCodeAndReason() {
    clientWriter.writeClose(1001, "Hello".encodeUtf8())
    assertData("888760b420bb635d68de0cd84f")
  }

  @Test fun closeWithOnlyReasonThrows() {
    clientWriter.writeClose(0, "Hello".encodeUtf8())
    assertData("888760b420bb60b468de0cd84f")
  }

  @Test fun closeCodeOutOfRangeThrows() {