code: def add_override(self, addr, key, value):
          
          address = Address(str(addr)).id
          _LOGGER.debug('New override for %s %s is %s', address, key, value)
          device_override = self._overrides.get(address, {})
          device_override[key] = value
          self._overrides[address] = device_override
docs: Register an attribute override for a device.