diff --git a/libs/binder/RpcState.h b/libs/binder/RpcState.h
index 6fb2e4a..892ecd6 100644
--- a/libs/binder/RpcState.h
+++ b/libs/binder/RpcState.h
@@ -258,6 +258,8 @@
         //
 
         // (no additional data specific to remote binders)
+
+        std::string toString() const;
     };
 
     // checks if there is any reference left to a node and erases it. If erase