CancelInstructionReport.sizeCancelled: "Required" but absent

[Simon McKenzie]

According to the API, the "sizeCancelled" field in CancelInstructionReport is "Required", but it's not always supplied (e.g. when the cancel fails):

{
    "status": "FAILURE",
    "errorCode": "BET_ACTION_ERROR",
    "marketId": "1.114434417",
    "instructionReports": [
        {
            "status": "FAILURE",
            "errorCode": "BET_TAKEN_OR_LAPSED",
            "instruction": {
                "betId": "38722401489"
            }
        }
    ]
}

Similarly, CurrentOrderSummary.matchedDate is marked as "required", but it's also sometimes absent (i.e. when the order hasn't been matched!)