Add topics type

pkg/core/log.go

@@ -4,7 +4,8 @@ type Log struct {
 	BlockNumber int64
 	TxHash      string
 	Address     string
-	Topics      map[int]string
-	Index       int64
-	Data        string
+	Topics
+	Index   int64
+	Data    string
+	Removed bool
 }

pkg/core/topics.go

@@ -0,0 +1,3 @@
+package core
+
+type Topics [4]string