### Question:
PetApi { public Pet getPetById(Long petId) throws RestClientException { Object postBody = null; if (petId == null) { throw new HttpClientErrorException(HttpStatus.BAD_REQUEST, "Missing the required parameter 'petId' when calling getPetById"); } final Map<String, Object> uriVariables = new HashMap<String, Object>(); uriVariables.put("petId", petId); String path = UriComponentsBuilder.fromPath("/pet/{petId}").buildAndExpand(uriVariables).toUriString(); final MultiValueMap<String, String> queryParams = new LinkedMultiValueMap<String, String>(); final HttpHeaders headerParams = new HttpHeaders(); final MultiValueMap<String, Object> formParams = new LinkedMultiValueMap<String, Object>(); final String[] accepts = { "application/xml", "application/json" }; final List<MediaType> accept = apiClient.selectHeaderAccept(accepts); final String[] contentTypes = { }; final MediaType contentType = apiClient.selectHeaderContentType(contentTypes); String[] authNames = new String[] { "api_key" }; ParameterizedTypeReference<Pet> returnType = new ParameterizedTypeReference<Pet>() {}; return apiClient.invokeAPI(path, HttpMethod.GET, queryParams, postBody, headerParams, formParams, accept, contentType, authNames, returnType); } PetApi(); @Autowired  PetApi(ApiClient apiClient); ApiClient getApiClient(); void setApiClient(ApiClient apiClient); void addPet(Pet body); void deletePet(Long petId, String apiKey); List<Pet> findPetsByStatus(List<String> status); List<Pet> findPetsByTags(List<String> tags); Pet getPetById(Long petId); void updatePet(Pet body); void updatePetWithForm(Long petId, String name, String status); ModelApiResponse uploadFile(Long petId, String additionalMetadata, File file);  }### Answer:
@Test public void getPetByIdTest() { Long petId = null; Pet response = api.getPetById(petId); }