The current PreCondition check in getProvider() method assumes that the node
is an OVS node. But this method is called for Openflow Node as well.
Hence the precondition fails.

java.lang.IllegalArgumentException: null
at com.google.common.base.Preconditions.checkArgument(Preconditions.java:76) ~[na:na]
at org.opendaylight.ovsdb.openstack.netvirt.impl.ProviderNetworkManagerImpl.getProvider(ProviderNetworkManagerImpl.java:40) ~[na:na]
at org.opendaylight.ovsdb.openstack.netvirt.SouthboundHandler.notifyNode(SouthboundHandler.java:366) ~[na:na]
at org.opendaylight.controller.switchmanager.internal.SwitchManager.notifyNode(SwitchManager.java:1827) ~[na:na]
at org.opendaylight.controller.switchmanager.internal.SwitchManager.addNode(SwitchManager.java:1049) ~[na:na]
at org.opendaylight.controller.switchmanager.internal.SwitchManager.updateNode(SwitchManager.java:1150) ~[na:na]
at org.opendaylight.controller.sal.implementation.internal.Inventory.updateNode(Inventory.java:115) ~[na:na]
at org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter.publishNodeUpdate(InventoryAndReadAdapter.java:728) ~[na:na]
at org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter.onNodeUpdated(InventoryAndReadAdapter.java:463) ~[na:na]
at org.opendaylight.controller.sal.compatibility.InventoryAndReadAdapter$$Broker$ListenerInvoker.onNotification(InventoryAndReadAdapter$$Broker$ListenerInvoker.java) ~[na:na]
at org.opendaylight.controller.sal.binding.impl.AbstractNotificationListenerRegistration.notify(AbstractNotificationListenerRegistration.java:38) ~[na:na]
at org.opendaylight.controller.sal.binding.impl.NotifyTask.run(NotifyTask.java:42) ~[na:na]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [na:1.7.0_40]
at java.util.concurrent.FutureTask.run(FutureTask.java:262) [na:1.7.0_40]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_40]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_40]
at java.lang.Thread.run(Thread.java:724) [na:1.7.0_40]