@classmethod
def DeregisterHelper(cls, analyzer_helper):
    """Deregisters a format analyzer helper.

    Args:
      analyzer_helper (AnalyzerHelper): analyzer helper.

    Raises:
      KeyError: if analyzer helper object is not set for the corresponding
          type indicator.
    """
    if analyzer_helper.type_indicator not in cls._analyzer_helpers:
        raise KeyError(
            'Analyzer helper object not set for type indicator: {0:s}.'.
            format(analyzer_helper.type_indicator))
    analyzer_helper = cls._analyzer_helpers[analyzer_helper.type_indicator]
    cls._FlushCache(analyzer_helper.format_categories)
    del cls._analyzer_helpers[analyzer_helper.type_indicator]
