payload.writeByte('0'.code)
    }
    serverWriter.writeMessageFrame(OPCODE_BINARY, payload.snapshot())

    // Write directly to the unbuffered sink. This ensures it will become single frame.
    assertData("827e") // 'e' == 4-byte follow-up length.
    assertData(format("%04X", payload.completeSegmentByteCount()))
    assertData(payload.readByteString())
  }

  @Test fun serverMessageLengthLong() {

2F87          ; mapped                 ; 821B          # 3.0  KANGXI RADICAL OPPOSE
2F88          ; mapped                 ; 821F          # 3.0  KANGXI RADICAL BOAT
2F89          ; mapped                 ; 826E          # 3.0  KANGXI RADICAL STOPPING
2F8A          ; mapped                 ; 8272          # 3.0  KANGXI RADICAL COLOR
2F8B          ; mapped                 ; 8278          # 3.0  KANGXI RADICAL GRASS