/// <summary>
/// Returns the only document of resultset, or null if resultset are empty; this method throw an exception if there not exactly one document in the sequence
/// </summary>
public Task <T> SingleOrDefaultAsync()
{
var tcs = new TaskCompletionSource <T>();
_liteDatabaseAsync.Enqueue(tcs, () => {
tcs.SetResult(_wrappedQuery.SingleOrDefault());
});
return(tcs.Task);
}
/// <summary>
/// Returns the only document of resultset, or null if resultset are empty; this method throw an exception if there not exactly one document in the sequence
/// </summary>
public Task <T> SingleOrDefaultAsync()
{
return(_liteDatabaseAsync.EnqueueAsync(
() => _wrappedQuery.SingleOrDefault()));
}