loadingValue method
Returns a cell that evaluates to the value of value
while an async value is loading..
The returned cell evaluates to the value of the cell value
if this cell
throws a PendingAsyncValueError exception.
A keyed cell is returned, which is unique for a given this
and value
.
Implementation
ValueCell<T> loadingValue(ValueCell<T> value) =>
onError<PendingAsyncValueError>(value);