code: def _className(self, name):
      if name not in self._class_names:
          res = self._NOT_CLASS_NAME_RE.sub("_", name)
          while res in self._class_names.values():
              res += "_"
          self._class_names[name] = res
      return self._class_names[name]
  
imports: import logging
  import re
  from io import StringIO
  from fontTools.feaLib import ast
  from fontTools.ttLib import TTFont, TTLibError
  from fontTools.voltLib import ast
  from fontTools.voltLib.parser import Parser
label_desc: Use image node_id 3 for calling the VoltToFea obj's underlying member method code with example usage: obj._className(name) and returns: self