code: async def on_raw_005(self, message):
          
          isupport = {}
  
          # Parse response.
          # Strip target (first argument) and 'are supported by this server' (last argument).
          for feature in message.params[1:-1]:
              if feature.startswith(FEATURE_DISABLED_PREFIX):
                  value = False
              elif '=' in feature:
                  feature, value = feature.split('=', 1)
              else:
                  value = True
              isupport[feature.upper()] = value
  
          # Update internal dict first.
          self._isupport.update(isupport)
  
          # And have callbacks update other internals.
          for entry, value in isupport.items():
              if value != False:
                  # A value of True technically means there was no value supplied; correct this for callbacks.
                  if value == True:
                      value = None
  
                  method = 'on_isupport_' + pydle.protocol.identifierify(entry)
                  if hasattr(self, method):
                      await getattr(self, method)(value)
docs: ISUPPORT indication.