code: func (h *Handler) GetTotalIncome(tkn string) (*uint, error) {
  	logger := h.logger.Add("method", "GetTotalIncome")
  
  	return h.uintFromQuery(logger, tkn,
  		`SELECT SUM(channels.receipt_balance)
  			FROM channels`)
  }
docs: // GetTotalIncome returns total receipt balance from all channels.