update

Packages/Runtime~/Core/Utility/Constant.cs

@@ -56,6 +56,7 @@ namespace BITKit
             public const string Internal = "Internal";
         }
         public const string Value = "Value";
+        public const string EmetyString = "";
         public static Func<bool> True => () => true;
         public static Func<bool> False => () => false;
         public class EmetyClass { }