### Question:
NetworkTopologyImpl implements NetworkTopology { public int getMaxLevel() { return maxLevel; } NetworkTopologyImpl(ConfigurationSource conf); @VisibleForTesting  NetworkTopologyImpl(NodeSchemaManager manager); void add(Node node); void remove(Node node); boolean contains(Node node); boolean isSameAncestor(Node node1, Node node2, int ancestorGen); boolean isSameParent(Node node1, Node node2); Node getAncestor(Node node, int ancestorGen); Node getNode(String loc); int getNumOfLeafNode(String loc); int getMaxLevel(); int getNumOfNodes(int level); Node chooseRandom(String scope); Node chooseRandom(String scope, List<String> excludedScopes); Node chooseRandom(String scope, Collection<Node> excludedNodes); Node chooseRandom(String scope, Collection<Node> excludedNodes,
      int ancestorGen); Node chooseRandom(String scope, List<String> excludedScopes,
      Collection<Node> excludedNodes, Node affinityNode, int ancestorGen); Node getNode(int leafIndex, String scope, List<String> excludedScopes,
      Collection<Node> excludedNodes, Node affinityNode, int ancestorGen); int getDistanceCost(Node node1, Node node2); List<? extends Node> sortByDistanceCost(Node reader,
      List<? extends Node> nodes, int activeLen); @Override String toString(); static final Logger LOG; }### Answer:
@Test public void testInitWithConfigFile() { ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); OzoneConfiguration conf = new OzoneConfiguration(); try { String filePath = classLoader.getResource( "./networkTopologyTestFiles/good.xml").getPath(); conf.set(ScmConfigKeys.OZONE_SCM_NETWORK_TOPOLOGY_SCHEMA_FILE, filePath); NetworkTopology newCluster = new NetworkTopologyImpl(conf); LOG.info("network topology max level = {}", newCluster.getMaxLevel()); } catch (Throwable e) { fail("should succeed"); } }