def initialize_bitarray(self):
self.bitarray = bitarray.bitarray(self.nbr_bits)<EOL>self.current_day_bitarray = bitarray.bitarray(self.nbr_bits)<EOL>self.bitarray.setall(False)<EOL>self.current_day_bitarray.setall(False)<EOL>
Initialize both bitarray.

        This BF contain two bit arrays instead of single one like a plain BF. bitarray
        is the main bit array where all the historical items are stored. It's the one
        used for the membership query. The second one, current_day_bitarray is the one
        used for creating the daily snapshot.