How to use the whisper.CACHE_HEADERS function in whisper

def __init__(self, corrupt_archive=False):
        self.corrupt_archive = corrupt_archive

        self.metadataFormat = whisper.metadataFormat
        self.archiveInfoFormat = whisper.archiveInfoFormat
        self.CACHE_HEADERS = whisper.CACHE_HEADERS

target_xff = struct.unpack("!f", struct.pack("!f", xff))[0]
            self.assertEqual(info2['xFilesFactor'], target_xff)

            # same aggregationMethod assertion again, but double-checking since
            # we are playing with packed values and seek()
            self.assertEqual(ag, info2['aggregationMethod'])

            with SimulatedCorruptWhisperFile():
                with AssertRaisesException(
                        whisper.CorruptWhisperFile(
                            'Unable to read header', self.filename)):
                    whisper.setAggregationMethod(self.filename, ag)

        whisper.LOCK = original_lock
        whisper.AUTOFLUSH = original_autoflush
        whisper.CACHE_HEADERS = original_caching

def test_normal(self):
        whisper.create(self.filename, [(1, 60), (60, 60)])

        whisper.CACHE_HEADERS = True
        whisper.info(self.filename)
        whisper.info(self.filename)
        whisper.CACHE_HEADERS = False

def test_setAggregation(self):
        """
        Create a db, change aggregation, xFilesFactor, then use info() to validate
        """
        original_lock = whisper.LOCK
        original_caching = whisper.CACHE_HEADERS
        original_autoflush = whisper.AUTOFLUSH

        whisper.LOCK = True
        whisper.AUTOFLUSH = True
        whisper.CACHE_HEADERS = True
        # create a new db with a valid configuration
        whisper.create(self.filename, self.retention)

        with AssertRaisesException(
                whisper.InvalidAggregationMethod(
                    'Unrecognized aggregation method: yummy beer')):
            whisper.setAggregationMethod(self.filename, 'yummy beer')

        # set setting every AggregationMethod available
        for ag in whisper.aggregationMethods:
          for xff in 0.0, 0.2, 0.4, 0.7, 0.75, 1.0:
            # original xFilesFactor
            info0 = whisper.info(self.filename)
            # optional xFilesFactor not passed
            old_ag = whisper.setAggregationMethod(self.filename, ag)

def test_setAggregation(self):
        """
        Create a db, change aggregation, xFilesFactor, then use info() to validate
        """
        original_lock = whisper.LOCK
        original_caching = whisper.CACHE_HEADERS
        original_autoflush = whisper.AUTOFLUSH

        whisper.LOCK = True
        whisper.AUTOFLUSH = True
        whisper.CACHE_HEADERS = True
        # create a new db with a valid configuration
        whisper.create(self.filename, self.retention)

        with AssertRaisesException(
                whisper.InvalidAggregationMethod(
                    'Unrecognized aggregation method: yummy beer')):
            whisper.setAggregationMethod(self.filename, 'yummy beer')

        # set setting every AggregationMethod available
        for ag in whisper.aggregationMethods:
          for xff in 0.0, 0.2, 0.4, 0.7, 0.75, 1.0:

def __exit__(self, *args, **kwargs):
        whisper.metadataFormat = self.metadataFormat
        whisper.archiveInfoFormat = self.archiveInfoFormat
        whisper.CACHE_HEADERS = self.CACHE_HEADERS