docs: def get_applications():
          """
          :return: all knows applications
          """
          LOGGER.debug("ApplicationService.get_applications")
          args = {'http_operation': 'GET', 'operation_path': ''}
          response = ApplicationService.requester.call(args)
          ret = None
          if response.rc == 0:
              ret = []
              for application in response.response_content['applications']:
                  ret.append(Application.json_2_application(application))
          elif response.rc != 404:
              err_msg = 'ApplicationService.get_applications - Problem while getting applications. ' \
                        'Reason: ' + str(response.response_content) + '-' + str(response.error_message) + \
                        " (" + str(response.rc) + ")"
              LOGGER.warning(err_msg)
          return ret