tests finally can works over pure novaclient/ssh
diff --git a/ssh_copy_directory.py b/ssh_copy_directory.py
index 5843c18..d074fcf 100644
--- a/ssh_copy_directory.py
+++ b/ssh_copy_directory.py
@@ -69,7 +69,7 @@
 
 
 def copy_paths(conn, paths):
-    sftp = conn._client.open_sftp()
+    sftp = conn.open_sftp()
     try:
         for src, dst in paths.items():
             try: