code: public static boolean isValid(String entry) {
  		boolean result = true;
  
  		try {
  			shouldRun(entry);
  		} catch (Exception ex) {
  			result = false;
  		}
  		return result;
  	}
docs: Determines if an entry is valid CRON syntax.
  
  @param   entry  The CRON entry.
  
  @return  True if the entry is valid CRON syntax.