core: types: use []byte for block Payload type (#101)

Change payload type to []byte instead of [][]byte to make it more
generic. The user of the consensus core should marshal the payload into
a byte slice by themselves.

1 files changed, 1 insertions, 1 deletions

diff --git a/core/interfaces.go b/core/interfaces.go
index 080db20..c8f57e9 100644
--- a/core/interfaces.go
+++ b/core/interfaces.go
@@ -30,7 +30,7 @@ import (
 // consensus core.
 type Application interface {
 	// PreparePayload is called when consensus core is preparing a block.
-	PreparePayloads(position types.Position) [][]byte
+	PreparePayload(position types.Position) []byte
 
 	// VerifyPayloads verifies if the payloads are valid.
 	VerifyPayloads(payloads [][]byte) bool