code: public ApiResponse<CertificateEnvelope> getWhitelistCertificateWithHttpInfo(String dtid) throws ApiException {
          com.squareup.okhttp.Call call = getWhitelistCertificateValidateBeforeCall(dtid, null, null);
          Type localVarReturnType = new TypeToken<CertificateEnvelope>(){}.getType();
          return apiClient.execute(call, localVarReturnType);
      }
docs: Get whitelist certificate of device type.
  Get whitelist certificate of device type.
  @param dtid Device Type ID. (required)
  @return ApiResponse&lt;CertificateEnvelope&gt;
  @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body