code: private int countNumberOfBitsSetToOne() {
  
      AtomicInteger numberOfBitsSetToOne = new AtomicInteger(0);
  
      stream(getBitArray()).forEach(bucket -> {
        for (int bitMask : BIT_MASKS) {
          if ((bucket & bitMask) != 0) {
            numberOfBitsSetToOne.incrementAndGet();
          }
        }
      });
  
      return numberOfBitsSetToOne.get();
    }
docs: /* (non-Javadoc)