code: def convert(self, tables=None):
      doc = VoltParser(self._file_or_path).parse()
  
      if tables is None:
          tables = TABLES
      if self._font is not None:
          self._glyph_order = self._font.getGlyphOrder()
  
      self._collectStatements(doc, tables)
      fea = self._buildFeatureFile(tables)
      return fea.asFea()
  
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 6 for calling the VoltToFea obj's underlying member method code with example usage: obj.convert(tables) and returns: fea