code: def _TableFactory(tag, stream, offset, length):
      
      TableClass = {
          'head': _HeadTable,
          'name': _NameTable,
      }.get(tag, _BaseTable)
      return TableClass(tag, stream, offset, length)
docs: Return an instance of |Table| appropriate to *tag*, loaded from
      *font_file* with content of *length* starting at *offset*.