### Question:
OvsdbHelper { public static OvsdbNodeAugmentation getManagerNode(OvsdbBridgeAugmentation bridge, DataBroker dataBroker) { OvsdbNodeRef bareIId = bridge.getManagedBy(); if (bareIId != null) { if (bareIId.getValue().getTargetType().equals(Node.class)) { ReadWriteTransaction transaction = dataBroker.newReadWriteTransaction(); InstanceIdentifier<Node> iid = (InstanceIdentifier<Node>) bareIId.getValue(); Optional<Node> nodeOptional = readFromDs(LogicalDatastoreType.OPERATIONAL, iid, transaction); if (nodeOptional.isPresent() && nodeOptional.get().getAugmentation(OvsdbNodeAugmentation.class) != null) { return nodeOptional.get().getAugmentation(OvsdbNodeAugmentation.class); } else { LOG.warn("Could not find ovsdb-node for connection for {}", bridge); } } else { LOG.warn("Bridge 'managedBy' non-ovsdb-node. bridge {} getManagedBy() {}", bridge, bareIId.getValue()); } } else { LOG.debug("Bridge 'managedBy' is null. bridge {}",bridge); } return null; }  static OvsdbBridgeAugmentation getOvsdbBridgeFromTerminationPoint(
            InstanceIdentifier<OvsdbTerminationPointAugmentation> tpIid, DataBroker dataBroker); static Node getNodeFromBridgeRef(OvsdbBridgeRef bridgeRef, DataBroker dataBroker); static OvsdbTerminationPointAugmentation getOvsdbTerminationPoint(
            InstanceIdentifier<OvsdbTerminationPointAugmentation> tpIid, DataBroker dataBroker); static Node getNode(Node node, List<TerminationPoint> tps,
            OvsdbBridgeAugmentation ovsdbBridgeAugmentation); static OvsdbBridgeAugmentation buildOvsdbBridgeAugmentation(OvsdbBridgeAugmentation bridge,
            OvsdbNodeAugmentation ovsdbNode); static List<TerminationPoint> buildTerminationPoints(OvsdbBridgeAugmentation bridge,
            OvsdbTerminationPointAugmentation ovsdbTp, AbstractTunnelType tunnelType); static String generateTpName(OvsdbBridgeAugmentation bridge, AbstractTunnelType tunnelType); static OvsdbTerminationPointAugmentation buildOvsdbTerminationPointAugmentation(
            OvsdbBridgeAugmentation bridge, List<Options> options, AbstractTunnelType tunnelType); static void setOption(List<Options> options, String key, String value); static IpAddress getManagerIp(OvsdbNodeAugmentation ovsdbNode); static IpAddress getNodeIp(OvsdbNodeAugmentation ovsdbNode); static List<ControllerEntry> buildControllerEntries(IpAddress ip); static OvsdbNodeAugmentation getManagerNode(OvsdbBridgeAugmentation bridge, DataBroker dataBroker); static Node getTopologyNode(InstanceIdentifier<Node> nodeIid, DataBroker dataBroker); static void createTunnelPort(InstanceIdentifier<Node> nodeIid,
            Node node, AbstractTunnelType tunnelType, DataBroker dataBroker);  }### Answer:
@Test public void testGetManagedNode_ManagedByNotSet() { assertNull(OvsdbHelper.getManagerNode(new OvsdbBridgeAugmentationBuilder().build(), dataBroker)); }
@SuppressWarnings("unchecked") @Test public void getManagedNode_InvalidTargetTypeForManagedBy() { final InstanceIdentifier<NetworkTopology> nodeIid = InstanceIdentifier.builder(NetworkTopology.class).build(); OvsdbBridgeAugmentationBuilder bridgeAugmentationBuilder = new OvsdbBridgeAugmentationBuilder(); bridgeAugmentationBuilder.setManagedBy(new OvsdbNodeRef(nodeIid)); assertNull(OvsdbHelper.getManagerNode(bridgeAugmentationBuilder.build(), dataBroker)); verify(readTransaction, never()).read(any(LogicalDatastoreType.class), any(InstanceIdentifier.class)); }