public async System.Threading.Tasks.Task <ICollection <HistoryData> > GetAllHistoryAsync(string username)
{
ICollection <IHistory> histories = await marketUsers.GetAllHistory(username);
ICollection <HistoryData> ret = new HashSet <HistoryData>();
foreach (IHistory his in histories)
{
ret.Add(new HistoryData(his));
}
return(ret);
}