diff --git a/core/state/state_witness.go b/core/state/state_witness.go
new file mode 100644
index 0000000000..e6acbc83ad
--- /dev/null
+++ b/core/state/state_witness.go
@@ -0,0 +1,35 @@
+package state
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type witness struct {
+	root   common.Hash
+	lists  []map[string][]byte
+	owners []common.Hash
+}
+
+func newWitness(originalRoot common.Hash) *witness {
+	return &witness{root: originalRoot}
+}
+
+func (w *witness) addAccessList(owner common.Hash, list map[string][]byte) {
+	if len(list) > 0 {
+		w.lists = append(w.lists, list)
+		w.owners = append(w.owners, owner)
+	}
+}
+
+func (w *witness) Dump() {
+	fmt.Printf("Root %x\n", w.root)
+	for i, list := range w.lists {
+		owner := w.owners[i]
+		fmt.Printf("Owner %#x, %d entries: \n", owner, len(list))
+		for path, v := range list {
+			fmt.Printf("- '%#x': %#x\n", path, v)
+		}
+	}
+}