class_docstr: Abstract base class from which all sentiment analyzers inherit.
  Should implement an ``analyze(text)`` method which returns either the
  results of analysis.
code: def __init__(self):
      self._trained = False
  
imports: from __future__ import absolute_import
  from abc import ABCMeta, abstractmethod
  import nltk
  from textblob.compat import with_metaclass
label_desc: Use image node_id 1 to create a new BaseSentimentAnalyzer object from inherited base classes:  with example: obj = BaseSentimentAnalyzer()