code: def get_max_col_num(mention):
      
      span = _to_span(mention, idx=-1)
      if span.sentence.is_tabular():
          return span.sentence.cell.col_end
      else:
          return None
docs: Return the largest column number that a Mention occupies.
  
      :param mention: The Mention to evaluate. If a candidate is given, default
          to its last Mention.
      :rtype: integer or None