1 files changed, 7 insertions, 2 deletions
diff --git a/mingling_core/src/asset/chain.rs b/mingling_core/src/asset/chain.rs
index 1ea1125..9f62228 100644
--- a/mingling_core/src/asset/chain.rs
+++ b/mingling_core/src/asset/chain.rs
@@ -1,8 +1,13 @@
+use std::fmt::Display;
+
 use crate::ChainProcess;
 
 pub mod error;
 
-pub trait Chain {
+pub trait Chain<G>
+where
+    G: Display,
+{
     type Previous;
-    fn proc(p: Self::Previous) -> impl Future<Output = ChainProcess> + Send;
+    fn proc(p: Self::Previous) -> impl Future<Output = ChainProcess<G>> + Send;
 }