code: def _val2str(v) -> str:
      # TODO: shall we raise error if non str, bool, number (or its container) parameters?
      return str(v) if not isinstance(v, str) else "'{}'".format(v)
  
file_path: tensorwatch/tensorwatch/notebook_maker.py
imports: import nbformat
  from nbformat.v4 import new_code_cell, new_markdown_cell, new_notebook
  from nbformat import v3, v4
  import codecs
  from os import linesep, path
  import uuid
  from .None import utils
  import re
  from typing import List
  from .lv_types import VisArgs
label_desc: Use image node_id 4 for calling the NotebookMaker obj's underlying member method code with example usage: obj._val2str(v) and returns: unknown