ENUM
enum CancelRejectReason {TOO_LATE_TO_CANCELUNKNOWN_ORDERBROKER_OPTIONORDER_ALREADY_IN_PENDING_CANCEL_OR_PENDING_REPLACE_STATUSUNABLE_TO_PROCESS_ORDER_MASS_CANCEL_REQUESTORIGMODTIME_DID_NOT_MATCH_LAST_TRANSACTTIMEDUPLICATE_CLORDID_RECEIVEDINVALID_PRICE_INCREMENTOTHER}