2 files changed, 8 insertions, 4 deletions
diff --git a/core/test/app.go b/core/test/app.go
index 60bc26f..d9582c9 100644
--- a/core/test/app.go
+++ b/core/test/app.go
@@ -97,15 +97,15 @@ func NewApp() *App {
 }
 
 // PreparePayload implements Application interface.
-func (app *App) PreparePayload(position types.Position) []byte {
-	return []byte{}
+func (app *App) PreparePayload(position types.Position) ([]byte, error) {
+	return []byte{}, nil
 }
 
 // PrepareWitness implements Application interface.
-func (app *App) PrepareWitness(height uint64) types.Witness {
+func (app *App) PrepareWitness(height uint64) (types.Witness, error) {
 	return types.Witness{
 		Height: height,
-	}
+	}, nil
 }
 
 // VerifyBlock implements Application.
diff --git a/core/test/governance.go b/core/test/governance.go
index de0ec21..88aab37 100644
--- a/core/test/governance.go
+++ b/core/test/governance.go
@@ -115,6 +115,10 @@ func (g *Governance) CRS(round uint64) common.Hash {
 	return g.crs[round]
 }
 
+// NotifyRoundHeight notifies governace contract to snapshot config.
+func (g *Governance) NotifyRoundHeight(round, height uint64) {
+}
+
 // ProposeCRS propose a CRS.
 func (g *Governance) ProposeCRS(signedCRS []byte) {
 	g.lock.Lock()