private Operation parseMethod(Method method) {
    Operation operation = new Operation();

    RequestMapping requestMapping = method.getAnnotation(RequestMapping.class);
    Class<?> responseClass = null;
    List<String> produces = new ArrayList<String>();
    List<String> consumes = new ArrayList<String>();
    String responseContainer = null;
    String operationId = method.getName();
    Map<String, Property> defaultResponseHeaders = null;
    Set<Map<String, Object>> customExtensions = null;

    ApiOperation apiOperation = method.getAnnotation(ApiOperation.class);

    if (apiOperation.hidden()) return null;
    if (!"".equals(apiOperation.nickname())) operationId = apiOperation.nickname();

    defaultResponseHeaders = parseResponseHeaders(apiOperation.responseHeaders());

    operation.summary(apiOperation.value()).description(apiOperation.notes());

    customExtensions = parseCustomExtensions(apiOperation.extensions());
    if (customExtensions != null) {
      for (Map<String, Object> extension : customExtensions) {
        if (extension != null) {
          for (Map.Entry<String, Object> map : extension.entrySet()) {
            operation.setVendorExtension(
                map.getKey().startsWith("x-") ? map.getKey() : "x-" + map.getKey(), map.getValue());
          }
        }
      }
    }

    if (apiOperation.response() != null && !Void.class.equals(apiOperation.response()))
      responseClass = apiOperation.response();
    if (!"".equals(apiOperation.responseContainer()))
      responseContainer = apiOperation.responseContainer();

    /// security
    if (apiOperation.authorizations() != null) {
      List<SecurityRequirement> securities = new ArrayList<SecurityRequirement>();
      for (Authorization auth : apiOperation.authorizations()) {
        if (auth.value() != null && !"".equals(auth.value())) {
          SecurityRequirement security = new SecurityRequirement();
          security.setName(auth.value());
          AuthorizationScope[] scopes = auth.scopes();
          for (AuthorizationScope scope : scopes) {
            if (scope.scope() != null && !"".equals(scope.scope())) {
              security.addScope(scope.scope());
            }
          }
          securities.add(security);
        }
      }
      if (securities.size() > 0) {
        for (SecurityRequirement sec : securities) operation.security(sec);
      }
    }

    if (responseClass == null) {
      // pick out response from method declaration
      LOG.info("picking up response class from method " + method);
      Type t = method.getGenericReturnType();
      responseClass = method.getReturnType();
      if (responseClass.equals(ResponseEntity.class)) {
        responseClass = getGenericSubtype(method.getReturnType(), method.getGenericReturnType());
      }
      if (!responseClass.equals(Void.class)
          && !"void".equals(responseClass.toString())
          && responseClass.getAnnotation(Api.class) == null) {
        LOG.info("reading model " + responseClass);
        Map<String, Model> models = ModelConverters.getInstance().readAll(t);
      }
    }
    if (responseClass != null
        && !responseClass.equals(Void.class)
        && !responseClass.equals(ResponseEntity.class)
        && responseClass.getAnnotation(Api.class) == null) {
      if (isPrimitive(responseClass)) {
        Property responseProperty = null;
        Property property = ModelConverters.getInstance().readAsProperty(responseClass);
        if (property != null) {
          if ("list".equalsIgnoreCase(responseContainer))
            responseProperty = new ArrayProperty(property);
          else if ("map".equalsIgnoreCase(responseContainer))
            responseProperty = new MapProperty(property);
          else responseProperty = property;
          operation.response(
              200,
              new Response()
                  .description("successful operation")
                  .schema(responseProperty)
                  .headers(defaultResponseHeaders));
        }
      } else if (!responseClass.equals(Void.class) && !"void".equals(responseClass.toString())) {
        Map<String, Model> models = ModelConverters.getInstance().read(responseClass);
        if (models.size() == 0) {
          Property pp = ModelConverters.getInstance().readAsProperty(responseClass);
          operation.response(
              200,
              new Response()
                  .description("successful operation")
                  .schema(pp)
                  .headers(defaultResponseHeaders));
        }
        for (String key : models.keySet()) {
          Property responseProperty = null;

          if ("list".equalsIgnoreCase(responseContainer))
            responseProperty = new ArrayProperty(new RefProperty().asDefault(key));
          else if ("map".equalsIgnoreCase(responseContainer))
            responseProperty = new MapProperty(new RefProperty().asDefault(key));
          else responseProperty = new RefProperty().asDefault(key);
          operation.response(
              200,
              new Response()
                  .description("successful operation")
                  .schema(responseProperty)
                  .headers(defaultResponseHeaders));
          swagger.model(key, models.get(key));
        }
        models = ModelConverters.getInstance().readAll(responseClass);
        for (String key : models.keySet()) {
          swagger.model(key, models.get(key));
        }
      }
    }

    operation.operationId(operationId);

    if (requestMapping.produces() != null) {
      for (String str : Arrays.asList(requestMapping.produces())) {
        if (!produces.contains(str)) {
          produces.add(str);
        }
      }
    }
    if (requestMapping.consumes() != null) {
      for (String str : Arrays.asList(requestMapping.consumes())) {
        if (!consumes.contains(str)) {
          consumes.add(str);
        }
      }
    }

    ApiResponses responseAnnotation = method.getAnnotation(ApiResponses.class);
    if (responseAnnotation != null) {
      updateApiResponse(operation, responseAnnotation);
    } else {
      ResponseStatus responseStatus = method.getAnnotation(ResponseStatus.class);
      if (responseStatus != null) {
        operation.response(
            responseStatus.value().value(), new Response().description(responseStatus.reason()));
      }
    }

    boolean isDeprecated = false;
    Deprecated annotation = method.getAnnotation(Deprecated.class);
    if (annotation != null) isDeprecated = true;

    boolean hidden = false;
    if (apiOperation != null) hidden = apiOperation.hidden();

    // process parameters
    Class[] parameterTypes = method.getParameterTypes();
    Type[] genericParameterTypes = method.getGenericParameterTypes();
    Annotation[][] paramAnnotations = method.getParameterAnnotations();
    // paramTypes = method.getParameterTypes
    // genericParamTypes = method.getGenericParameterTypes
    for (int i = 0; i < parameterTypes.length; i++) {
      Type type = genericParameterTypes[i];
      List<Annotation> annotations = Arrays.asList(paramAnnotations[i]);
      List<Parameter> parameters = getParameters(type, annotations);

      for (Parameter parameter : parameters) {
        operation.parameter(parameter);
      }
    }

    if (operation.getResponses() == null) {
      operation.defaultResponse(new Response().description("successful operation"));
    }

    // Process @ApiImplicitParams
    this.readImplicitParameters(method, operation);

    return operation;
  }
  public Operation operation(ObjectNode obj, String location, ParseResult result) {
    if (obj == null) {
      return null;
    }
    Operation output = new Operation();
    ArrayNode array = getArray("tags", obj, false, location, result);
    List<String> tags = tagStrings(array, location, result);
    if (tags != null) {
      output.tags(tags);
    }
    String value = getString("summary", obj, false, location, result);
    output.summary(value);

    value = getString("description", obj, false, location, result);
    output.description(value);

    ObjectNode externalDocs = getObject("externalDocs", obj, false, location, result);
    ExternalDocs docs = externalDocs(externalDocs, location, result);
    output.setExternalDocs(docs);

    value = getString("operationId", obj, false, location, result);
    output.operationId(value);

    array = getArray("consumes", obj, false, location, result);
    if (array != null) {
      if (array.size() == 0) {
        output.consumes(Collections.<String>emptyList());
      } else {
        Iterator<JsonNode> it = array.iterator();
        while (it.hasNext()) {
          JsonNode n = it.next();
          String s = getString(n, location + ".consumes", result);
          if (s != null) {
            output.consumes(s);
          }
        }
      }
    }
    array = getArray("produces", obj, false, location, result);
    if (array != null) {
      if (array.size() == 0) {
        output.produces(Collections.<String>emptyList());
      } else {
        Iterator<JsonNode> it = array.iterator();
        while (it.hasNext()) {
          JsonNode n = it.next();
          String s = getString(n, location + ".produces", result);
          if (s != null) {
            output.produces(s);
          }
        }
      }
    }
    ArrayNode parameters = getArray("parameters", obj, false, location, result);
    output.setParameters(parameters(parameters, location, result));

    ObjectNode responses = getObject("responses", obj, true, location, result);
    output.setResponses(responses(responses, location, result));

    array = getArray("schemes", obj, false, location, result);
    if (array != null) {
      Iterator<JsonNode> it = array.iterator();
      while (it.hasNext()) {
        JsonNode n = it.next();
        String s = getString(n, location + ".schemes", result);
        if (s != null) {
          Scheme scheme = Scheme.forValue(s);
          if (scheme != null) {
            output.scheme(scheme);
          }
        }
      }
    }
    Boolean deprecated = getBoolean("deprecated", obj, false, location, result);
    if (deprecated != null) {
      output.setDeprecated(deprecated);
    }
    array = getArray("security", obj, false, location, result);
    List<SecurityRequirement> security = securityRequirements(array, location, result);
    if (security != null) {
      List<Map<String, List<String>>> ss = new ArrayList<>();
      for (SecurityRequirement s : security) {
        if (s.getRequirements() != null && s.getRequirements().size() > 0) {
          ss.add(s.getRequirements());
        }
      }
      output.setSecurity(ss);
    }

    // extra keys
    Set<String> keys = getKeys(obj);
    for (String key : keys) {
      if (key.startsWith("x-")) {
        output.setVendorExtension(key, extension(obj.get(key)));
      } else if (!OPERATION_KEYS.contains(key)) {
        result.extra(location, key, obj.get(key));
      }
    }

    return output;
  }