class_docstr: Base ``History`` interface.
class_docstr_tok: ["Base","``","History","``","interface","."]
docstr: Append string to history. 
docstr_tok: ["Append","string","to","history","."]
code: def append(self, string):
      "Append string to history."
  
imports: from __future__ import unicode_literals
  from abc import ABCMeta, abstractmethod
  from six import with_metaclass
  import datetime
  import os
label_desc: Use image node_id 1 for calling the History obj's underlying member method code with example usage: obj.append(string) without return types