/// <inheritdoc />
protected override async Task <IReadOnlyDictionary <string, IReadOnlyCollection <IModel> > > GetItem(string id, CancellationToken cancellationToken = default)
{
// Get the models
var models = await m_provider
// Query the models from a given book
.GetBookModelsAsync(IdToInt(id), cancellationToken)
// Materialize the result
.ToListAsync(cancellationToken)
.ConfigureAwait(false);
// Return the result
return(models
// Group the models by their names
.GroupBy(model => model.Name)
// Materialize the items into a map of model name to concrete models
.ToDictionary(group => group.Key, group => group.ToReadOnlyCollection()));
}