docs: @Override
  	public int getMinPrefixLengthForBlock() {
  		int count = getDivisionCount();
  		int totalPrefix = getBitCount();
  		for(int i = count - 1; i >= 0 ; i--) {
  			AddressDivisionBase div = getDivision(i);
  			int segBitCount = div.getBitCount();
  			int segPrefix = div.getMinPrefixLengthForBlock();
  			if(segPrefix == segBitCount) {
  				break;
  			} else {
  				totalPrefix -= segBitCount;
  				if(segPrefix != 0) {
  					totalPrefix += segPrefix;
  					break;
  				}
  			}
  		}
  		return totalPrefix;
  	}