docstr: Append a note to the bottom of the summary table. In ASCII tables,
  the note will be wrapped to table width. Notes are not indented.
docstr_tok: ["Append","a","note","to","the","bottom","of","the","summary","table",".","In","ASCII","tables",",","the","note","will","be","wrapped","to","table","width",".","Notes","are","not","indented","."]
code: def add_text(self, string):
      """Append a note to the bottom of the summary table. In ASCII tables,
      the note will be wrapped to table width. Notes are not indented.
      """
      self.extra_txt.append(string)
  
imports: from statsmodels.compat.pandas import FUTURE_STACK
  from statsmodels.compat.python import lzip
  import datetime
  from functools import reduce
  import re
  import textwrap
  import numpy
  import pandas
  from .table import SimpleTable
  from .tableformatting import fmt_latex, fmt_txt
label_desc: Use image node_id 9 for calling the Summary obj's underlying member method code with example usage: obj.add_text(string) without return types