migrate code over from xos repo

Change-Id: I764ac3196babdb1ce78dded2b2d8d6ad6e965ca6
diff --git a/xos/synchronizer/model_policies/model_policy_Sliver.py b/xos/synchronizer/model_policies/model_policy_Sliver.py
new file mode 100644
index 0000000..a13428d
--- /dev/null
+++ b/xos/synchronizer/model_policies/model_policy_Sliver.py
@@ -0,0 +1,13 @@
+
+def handle(instance):
+    from core.models import Controller, ControllerSlice, ControllerNetwork, NetworkSlice
+
+    networks = [ns.network for ns in NetworkSlice.objects.filter(slice=instance.slice)]
+    controller_networks = ControllerNetwork.objects.filter(network__in=networks,
+                                                                controller=instance.node.site_deployment.controller)
+
+    for cn in controller_networks:
+        if (cn.lazy_blocked):	
+		cn.lazy_blocked=False
+		cn.backend_register = '{}'
+		cn.save()