code: func (s *Session) Safe() (safe *Safe) {
  	s.m.Lock()
  	defer s.m.Unlock()
  	if s.safeOp != nil {
  		cmd := s.safeOp.query.(*getLastError)
  		safe = &Safe{WTimeout: cmd.WTimeout, FSync: cmd.FSync, J: cmd.J}
  		switch w := cmd.W.(type) {
  		case string:
  			safe.WMode = w
  		case int:
  			safe.W = w
  		}
  	}
  	return
  }
docs: // Safe returns the current safety mode for the session.