Avoid libvirt domain lookup if VM has not been created

lib/sahara/session/libvirt.rb

@@ -8,7 +8,7 @@ def initialize(machine)
         @machine=machine
         @sandboxname="sahara-sandbox"
         @connection=connect_to_libvirt
-        @domain = @connection.client.lookup_domain_by_uuid(@machine.id)
+        @domain=get_domain
       end
 
       # based on VagrantPlugins::ProviderLibvirt::Action::ConnectLibvirt
@@ -53,6 +53,14 @@ def connect_to_libvirt
         end
       end
 
+      def get_domain
+        if is_vm_created?
+          return @connection.client.lookup_domain_by_uuid(@machine.id)
+        else
+          return nil
+        end
+      end
+
       def get_snapshot_if_exists
         # if we can get snapshot description without exception it exists
         begin