code: def DeregisterAnalyzer(cls, analyzer_class):
      
      analyzer_name = analyzer_class.NAME.lower()
      if analyzer_name not in cls._analyzer_classes:
        raise KeyError('analyzer class not set for name: {0:s}'.format(
            analyzer_class.NAME))
  
      del cls._analyzer_classes[analyzer_name]
docs: Deregisters a analyzer class.
  
      The analyzer classes are identified based on their lower case name.
  
      Args:
        analyzer_class (type): class object of the analyzer.
  
      Raises:
        KeyError: if analyzer class is not set for the corresponding name.