docs: def get_path_str(self, sep=os.path.sep, type_str=None):
          """Get path from root to this node.
  
          Args:
              sep: str
                  One or more characters to insert between each element in the path.
                  Defaults to "/" on Unix and "\" on Windows.
  
              type_str:
                  SUBJECT_NODE_TAG, TYPE_NODE_TAG or None. If set, only include
                  information from nodes of that type.
  
          Returns:
              str: String describing the path from the root to this node.
  
          """
          return sep.join(
              list(
                  reversed(
                      [
                          v.label_str
                          for v in self.parent_gen
                          if type_str in (None, v.type_str)
                      ]
                  )
              )
          )