'Cleanup internal data.'

@requires_setup
def cleanup(self):

    self.db.execute(('DELETE    FROM    %s    WHERE    1=1' % self.table_name))
    old_urls = self.urls
    self.urls = DiskSet(table_prefix='kb_urls')
    old_urls.cleanup()
    old_fuzzable_requests = self.fuzzable_requests
    self.fuzzable_requests = DiskSet(table_prefix='kb_fuzzable_requests')
    old_fuzzable_requests.cleanup()
    self.observers.clear()
