diff --git a/tests/functional/pyocf/types/data.py b/tests/functional/pyocf/types/data.py
index 6e14266..6e6eec3 100644
--- a/tests/functional/pyocf/types/data.py
+++ b/tests/functional/pyocf/types/data.py
@@ -223,3 +223,7 @@ class Data:
         m = md5()
         m.update(string_at(self.handle, self.size))
         return m.hexdigest()
+
+    def get_bytes(self):
+        return string_at(self.handle, self.size)
+
diff --git a/tests/functional/pyocf/types/volume.py b/tests/functional/pyocf/types/volume.py
index e4a31ef..1b54b9d 100644
--- a/tests/functional/pyocf/types/volume.py
+++ b/tests/functional/pyocf/types/volume.py
@@ -312,6 +312,9 @@ class Volume(Structure):
         m.update(string_at(self._storage, self.size))
         return m.hexdigest()
 
+    def get_bytes(self):
+        return string_at(self._storage, self.size)
+
 
 class ErrorDevice(Volume):
     def __init__(