package storage import "errors" type Balance struct { ID string `json:"id"` At int64 `json:"at"` Is float32 `json:"is"` } func (s *Storage) CurrentBalances(accounts ...Account) ([]Balance, error) { return nil, errors.New("not impl") } func (s *Storage) BalancesOverTime(from, to int64, accounts ...Account) ([]Balance, error) { return nil, errors.New("not impl") }