### Question:
RequestOperationLevel { public static String getExternalLevelName(String internal) { for (String [] pair : LEVEL_ALIASES) { if (pair[INTERNAL_NAME_COLUMN].equals(internal)) { return pair[ALIAS_COLUMN]; } } String message = String.format("Unknown internal " + "operation level name %s", internal); throw new IllegalArgumentException(message); } RequestOperationLevel(Resource.Type level, String clusterName,
                               String serviceName, String hostComponentName,
                               String hostName);  RequestOperationLevel(Map<String, String> requestInfoProperties); static String getInternalLevelName(String external); static String getExternalLevelName(String internal); Resource.Type getLevel(); String getClusterName(); String getServiceName(); String getHostComponentName(); String getHostName(); @Override String toString(); static Map<String, String> propertiesFor(Resource.Type type, String clusterName); static final String OPERATION_LEVEL_ID; static final String OPERATION_CLUSTER_ID; static final String OPERATION_SERVICE_ID; static final String OPERATION_HOSTCOMPONENT_ID; static final String OPERATION_HOST_NAME; }### Answer:
@Test public void testGetExternalLevelName() throws Exception { String external = RequestOperationLevel.getExternalLevelName(hostComponent); assertEquals(external, host_component); try { RequestOperationLevel.getExternalLevelName("Wrong_param"); fail("Should throw exception"); } catch (IllegalArgumentException e) { } }