docs: public static String toSizeUnit(Long bytes, int scale) {
  		if (bytes == null) {
  			return "n/a";
  		}
  		if (bytes < K) {
  			return String.format("%4d", bytes);
  		}
  
  		if (bytes < M) {
  			return String.format("%" + (scale == 0 ? 4 : 5 + scale) + '.' + scale + "fk", bytes * 1d / K);
  		}
  
  		if (bytes < G) {
  			return String.format("%" + (scale == 0 ? 4 : 5 + scale) + '.' + scale + "fm", bytes * 1d / M);
  		}
  
  		if (bytes < T) {
  			return String.format("%" + (scale == 0 ? 4 : 5 + scale) + '.' + scale + "fg", bytes * 1d / G);
  		}
  
  		return String.format("%" + (scale == 0 ? 4 : 5 + scale) + '.' + scale + "ft", bytes * 1d / T);
  	}