[CORD-1445] Refactored vPGWC for CORD-3.0

Change-Id: I6024d0e4eae62ffbce84d6deef0be5c8918f7986
diff --git a/xos/tosca/resources/VPGWCTenant.py b/xos/tosca/resources/VPGWCTenant.py
index 434972a..9b47e3b 100644
--- a/xos/tosca/resources/VPGWCTenant.py
+++ b/xos/tosca/resources/VPGWCTenant.py
@@ -1,18 +1,20 @@
-from services.vpgwc.models import VPGWCTenant, VPGWCService
 from xosresource import XOSResource
+from core.models import Tenant, Service
+from services.vpgwc.models import VPGWCTenant
 
 class XOSVPGWCTenant(XOSResource):
     provides = "tosca.nodes.VPGWCTenant"
     xos_model = VPGWCTenant
-    copyin_props = ["s5s8_pgw_tag", "display_message", "image_name"]
     name_field = None
+    copyin_props = ["s5s8_pgw_tag", "display_message", "image_name"]
 
     def get_xos_args(self, throw_exception=True):
         args = super(XOSVPGWCTenant, self).get_xos_args()
 
-        provider_name = self.get_requirement("tosca.relationships.MemberOfService", throw_exception=throw_exception)
+        # ExampleTenant must always have a provider_service
+        provider_name = self.get_requirement("tosca.relationships.TenantOfService", throw_exception=True)
         if provider_name:
-            args["provider_service"] = self.get_xos_object(VPGWCService, throw_exception=throw_exception, name=provider_name)
+            args["provider_service"] = self.get_xos_object(Service, throw_exception=True, name=provider_name)
 
         return args
 
@@ -20,7 +22,7 @@
         args = self.get_xos_args(throw_exception=False)
         provider_service = args.get("provider", None)
         if provider_service:
-            return [ self.get_xos_object(provider_service=provider_service) ]
+            return [self.get_xos_object(provider_service=provider_service)]
         return []
 
     def postprocess(self, obj):
@@ -28,4 +30,3 @@
 
     def can_delete(self, obj):
         return super(XOSVPGWCTenant, self).can_delete(obj)
-