code: static int getBitsPerItemForFpRate(double fpProb,double loadFactor) {
  		/*
  		 * equation from Cuckoo Filter: Practically Better Than Bloom Bin Fan,
  		 * David G. Andersen, Michael Kaminsky , Michael D. Mitzenmacher
  		 */
  		return DoubleMath.roundToInt(DoubleMath.log2((1 / fpProb) + 3) / loadFactor, RoundingMode.UP);
  	}
docs: Calculates how many bits are needed to reach a given false positive rate.
  
  @param fpProb
  the false positive probability.
  @return the length of the tag needed (in bits) to reach the false
  positive rate.