docs: def add_volume(self, path):
          """
          Add a shared volume (i.e. with the ``VOLUME`` command). Not actually written until finalized.
  
          :param path: Path to the shared volume.
          """
          self.check_not_finalized()
          if self.volumes is None:
              self.volumes = [path]
          else:
              self.volumes.append(path)