@@ -0,0 +1,13 @@
+import java.security.NoSuchAlgorithmException;
+
+public interface ObjectHashable {
+    default String hexDigest() throws NoSuchAlgorithmException {
+        StringBuilder sb = new StringBuilder();
+        for (byte b : getBytes()) {
+            sb.append(String.format("%02x", b));
+        }
+        return sb.toString();
+    }
+    
+    byte[] getBytes() throws NoSuchAlgorithmException;
+}