code: def GetVolumeByIdentifier(self, volume_identifier):
      
      if not self._is_parsed:
        self._Parse()
        self._is_parsed = True
  
      return self._volumes[volume_identifier]
docs: Retrieves a specific volume based on the identifier.
  
      Args:
        volume_identifier (str): identifier of the volume within
            the volume system.
  
      Returns:
        Volume: a volume.