apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/api/AdminServiceAPI.java/ReleaseAPI/createGrayDeletionRelease
class ReleaseAPI:    public ReleaseDTO createGrayDeletionRelease(String appId, Env env, String clusterName, String namespace,
                                    String releaseName, String releaseComment, String operator,
                                    boolean isEmergencyPublish, Set<String> grayDelKeys) {
      HttpHeaders headers = new HttpHeaders();
      headers.setContentType(MediaType.parseMediaType(MediaType.APPLICATION_FORM_URLENCODED_VALUE + ";charset=UTF-8"));
      MultiValueMap<String, String> parameters = new LinkedMultiValueMap<>();
      parameters.add("releaseName", releaseName);
      parameters.add("comment", releaseComment);
      parameters.add("operator", operator);
      parameters.add("isEmergencyPublish", String.valueOf(isEmergencyPublish));
      grayDelKeys.forEach(key -> parameters.add("grayDelKeys",key));
      HttpEntity<MultiValueMap<String, String>> entity =
              new HttpEntity<>(parameters, headers);
      ReleaseDTO response = restTemplate.post(
              env, "apps/{appId}/clusters/{clusterName}/namespaces/{namespaceName}/gray-del-releases", entity,
              ReleaseDTO.class, appId, clusterName, namespace);
      return response;
    }