code: def AddKeyByPath(self, key_path, registry_key):
      
      if not key_path.startswith(definitions.KEY_PATH_SEPARATOR):
        raise ValueError('Key path does not start with: {0:s}'.format(
            definitions.KEY_PATH_SEPARATOR))
  
      if not self._root_key:
        self._root_key = FakeWinRegistryKey(self._key_path_prefix)
  
      path_segments = key_paths.SplitKeyPath(key_path)
      parent_key = self._root_key
      for path_segment in path_segments:
        try:
          subkey = FakeWinRegistryKey(path_segment)
          parent_key.AddSubkey(subkey)
        except KeyError:
          subkey = parent_key.GetSubkeyByName(path_segment)
  
        parent_key = subkey
  
      parent_key.AddSubkey(registry_key)
docs: Adds a Windows Registry key for a specific key path.
  
      Args:
        key_path (str): Windows Registry key path to add the key.
        registry_key (WinRegistryKey): Windows Registry key.
  
      Raises:
        KeyError: if the subkey already exists.
        ValueError: if the Windows Registry key cannot be added.