code: func (h *Handler) GetLastBlockNumber(tkn string) (*uint64, error) {
  	logger := h.logger.Add("method", "GetLastBlockNumber")
  
  	if !h.token.Check(tkn) {
  		logger.Warn("access denied")
  		return nil, ErrAccessDenied
  	}
  
  	minConfirmations, err := h.minConfirmations(logger)
  	if err != nil {
  		return nil, err
  	}
  
  	var queryRet sql.NullInt64
  	row := h.db.QueryRow("SELECT max((data->'ethereumLog'->>'block') :: bigint) from jobs")
  	if err := row.Scan(&queryRet); err != nil {
  		logger.Error(err.Error())
  		return nil, ErrInternal
  	}
  
  	logger.Error(fmt.Sprint(queryRet.Int64))
  	ret := uint64(queryRet.Int64) + minConfirmations
  	return &ret, nil
  }
docs: // GetLastBlockNumber returns last known block number.