Fixed wrong error message, fixed trade volume deserialization

.gitignore

@@ -348,3 +348,4 @@ healthchecksdb
 
 # Backup folder for Package Reference Convert tool in Visual Studio 2017
 MigrationBackup/
+Kraken.Net/Kraken.Net.xml

Kraken.Net/KrakenHelpers.cs

@@ -17,7 +17,7 @@ public static string ValidateKrakenSymbol(this string symbolString)
             if (string.IsNullOrEmpty(symbolString))
                 throw new ArgumentException("Symbol is not provided");
             if (!Regex.IsMatch(symbolString, "^(([a-z]|[A-Z]|[0-9]|\\.){5,})$"))
-                throw new ArgumentException($"{symbolString} is not a valid Kraken symbol. Should be [QuoteCurrency][BaseCurrency], e.g. ETHXBT");
+                throw new ArgumentException($"{symbolString} is not a valid Kraken symbol. Should be [BaseCurrency][QuoteCurrency], e.g. ETHXBT");
             return symbolString;
         }
 

Kraken.Net/Objects/KrakenTradeVolume.cs

@@ -21,12 +21,12 @@ public class KrakenTradeVolume
         /// <summary>
         /// Fees structure
         /// </summary>
-        public IEnumerable<KrakenFeeStruct> Fees { get; set; } = Array.Empty<KrakenFeeStruct>();
+        public Dictionary<string, KrakenFeeStruct> Fees { get; set; } = new Dictionary<string, KrakenFeeStruct>();
         /// <summary>
         /// Maker fees structure
         /// </summary>
         [JsonProperty("fees_maker")]
-        public IEnumerable<KrakenFeeStruct> MakerFees { get; set; } = Array.Empty<KrakenFeeStruct>();
+        public Dictionary<string, KrakenFeeStruct> MakerFees { get; set; } = new Dictionary<string, KrakenFeeStruct>();
     }
 
     /// <summary>