subscription source realm

1func CancelSubscription(cur realm, subID int64)

1func CreateSubscription(cur realm, payee address, amountPerPeriod int64, periodBlocks int64) int64

1func GetSubAmountPerPeriod(subID int64) int64

1func GetSubBalance(subID int64) int64

1func GetSubNextDueHeight(subID int64) int64

1func IsSubActive(subID int64) bool

1func TopUp(cur realm, subID int64)

1func Withdraw(cur realm, subID int64)

 1type Subscription struct {
 2	ID              int64
 3	Payer           address
 4	Payee           address
 5	AmountPerPeriod int64
 6	PeriodBlocks    int64
 7	Balance         int64
 8	NextDueHeight   int64
 9	Active          bool
10}