public async Task <(bool, T)> GetAsync(int pos, CancellationToken cancellationToken)
{
if (pos == -1)
{
return(false, default(T));
}
if (Obtained.Count < pos)
{
return(true, Obtained[pos]);
}
while (currentpos < pos)
{
if (await en.MoveNext(cancellationToken).ConfigureAwait(false))
{
Obtained.Add(en.Current);
currentpos++;
}
else
{
return(false, default(T));
}
}
return(true, Obtained[pos]);
}