public ChangeCcyPairState(string ccyPairId, string market, CcyPairState state) : base(ccyPairId)
 {
     State  = state;
     Market = market;
 }
 public CurrencyPairStateChanged(string ccyPairId, string traderId, CcyPairState state) : base(ccyPairId, Guid.NewGuid())
 {
     State    = state;
     TraderId = traderId;
 }