code: def _get_support_sound_mode_avr(self):
          
          # Set sound mode tags to be checked if available
          relevant_tags = {"selectSurround": None, "SurrMode": None}
  
          # Get status XML from Denon receiver via HTTP
          try:
              root = self.get_status_xml(self._urls.status)
          except (ValueError, requests.exceptions.RequestException):
              pass
          else:
              # Process the tags from this XML
              relevant_tags = self._get_status_from_xml_tags(root, relevant_tags)
  
          # Second option to update variables from different source
          if relevant_tags:
              try:
                  root = self.get_status_xml(self._urls.mainzone)
              except (ValueError,
                      requests.exceptions.RequestException):
                  pass
              else:
                  # Get the tags from this XML
                  relevant_tags = self._get_status_from_xml_tags(root,
                                                                 relevant_tags)
  
          # if sound mode not found in the status XML, return False
          if relevant_tags:
              self._support_sound_mode = False
              return False
          # if sound mode found, the relevant_tags are empty: return True.
          self._support_sound_mode = True
          return True
docs: Get if sound mode is supported from device.
  
          Method queries device via HTTP.
          Returns "True" if sound mode supported and "False" if not.
          This method is for pre 2016 AVR(-X) devices