### Question:
WSCXMLServiceProvider implements ServiceProvider<String> { public Service<String> getService(String serviceID) { XMLService xmlService = nameIndex.get(serviceID); if (xmlService != null) { ResourceService<String> s = new ResourceService<String>(xmlService.getName()); Set<String> inputs = new HashSet<String>(); for (XMLInstance input : xmlService.getInputs().getInstances()) { inputs.add(input.getName()); } Set<String> outputs = new HashSet<String>(); for (XMLInstance output : xmlService.getOutputs().getInstances()) { outputs.add(output.getName()); } SignatureIO<String> signature = new SignatureIO<String>(inputs, outputs); ResourceOperation<String> op = new ResourceOperation<String>(serviceID + operationSuffix, signature); s.addOperation(op); return s; } return null; } WSCXMLServiceProvider(InputStream serviceStream);  WSCXMLServiceProvider(File xmlServices); Service<String> getService(String serviceID); @Override Operation<String> getOperation(String operationID); @Override Iterable<Operation<String>> getOperationsWithInput(String inputInstance); @Override Iterable<Operation<String>> getOperationsWithOutput(String outputInstance); @Override Iterable<Operation<String>> getOperations(); @Override Iterable<Service<String>> getServices(); @Override Set<String> listOperations(); @Override Set<String> listServices(); static final String operationSuffix; }### Answer:
@Test public void testGetNonExistingService() throws Exception { Service<String> service = provider.getService("serv699915007Operation"); assertNull(service); }