docs: def create_response_signature(self, string_message, zone):
          """ Basic helper function to keep code clean for defining a response message signature """
  
          zz = ''
          if zone is not None:
              zz = hex(int(zone)-1).replace('0x', '')  # RNET requires zone value to be zero based
          string_message = string_message.replace('@zz', zz)  # Replace zone parameter
          return string_message