code: public static long _9sComplement(long creationTime) {
  		String time = String.valueOf(creationTime);
  		char[] timeArr = time.toCharArray();
  		StringBuilder sb = new StringBuilder();
  		for(char c : timeArr) {
  			sb.append(9 - Character.getNumericValue(c));
  		}
  		
  		return Long.parseLong(sb.toString());
  	}
docs: Return a 9's complement of the given timestamp. Since AsyncHBase doesn't allow a reverse scan and we want to scan data in descending order
  of creation time.
  
  @param 	creationTime	creation time
  @return 	The 9's complement of the given timestamp.