clientSellCoveredBeforeDate method
Implementation
num clientSellCoveredBeforeDate(int herderId, DateTime date) =>
where((t) => t.contactIdString == herderId.toString())
.where((t) => t.status == true)
.where((t) => t.date.isBefore(date))
.where((t) => t.ticketType == TicketType.sellCovered)
.fold(0.0, (prev, e) => prev + e.received);