code: def AddValue(self, registry_value):
      
      name = registry_value.name.upper()
      if name in self._values:
        raise KeyError(
            'Value: {0:s} already exists.'.format(registry_value.name))
  
      self._values[name] = registry_value
docs: Adds a value.
  
      Args:
        registry_value (WinRegistryValue): Windows Registry value.
  
      Raises:
        KeyError: if the value already exists.