docs: def _finalize_metadata(self, node):
          """Convert node metadata back into a standard dictionary and list.
          """
          final = {}
          for key, val in iter(node.metadata.items()):
              #val = list(val)
              #if isinstance(val[0], tuple):
              #    val = [dict(v) for v in val]
              final[key] = list(val)
          node.metadata = final
          return node