diff --git a/src/Yitter.IdGenerator/IIdGenerator.cs b/src/Yitter.IdGenerator/IIdGenerator.cs
index 197af90..d96e225 100644
--- a/src/Yitter.IdGenerator/IIdGenerator.cs
+++ b/src/Yitter.IdGenerator/IIdGenerator.cs
@@ -16,5 +16,7 @@ namespace Yitter.IdGenerator
         Action<OverCostActionArg> GenIdActionAsync { get; set; }
 
         long NewLong();
+
+        // Guid NewGuid();
     }
 }