fix bugs
diff --git a/planetstack/observer/openstacksyncstep.py b/planetstack/observer/openstacksyncstep.py
index 515ff09..4f2a260 100644
--- a/planetstack/observer/openstacksyncstep.py
+++ b/planetstack/observer/openstacksyncstep.py
@@ -10,5 +10,5 @@
         SyncStep.__init__(self, **args)
         return
 
-    def __call__(self):
-        return self.call()
+    def __call__(self, **args):
+        return self.call(**args)