code: public void recordPassword(ModeledUser user)
              throws GuacamoleException {
  
          // Retrieve password policy from environment
          PasswordPolicy policy = environment.getPasswordPolicy();
  
          // Nothing to do if history is not being recorded
          int historySize = policy.getHistorySize();
          if (historySize <= 0)
              return;
          
          // Store previous password in history
          passwordRecordMapper.insert(user.getPasswordRecord(), historySize);
  
      }
docs: Records the password that was associated with the given user at the time
  the user was queried, such that future attempts to set that same password
  for that user will be denied. The number of passwords remembered for each
  user is limited by the password policy.
  
  @param user
  The user whose password should be recorded within the password
  history.
  
  @throws GuacamoleException
  If the password policy cannot be parsed.