public IndividualEntity Retrieve(int id)
{
// Guard against invalid arguments.
if (id < 1)
{
throw new ArgumentOutOfRangeException("id");
}
try
{
// Retrieve returns null if a record isn't found.
return(repository.Retrieve(id));
}
catch (Exception exception)
{
// Throw an exception if the Id was not returned.
throw new InvalidOperationException("Failed to retrieve.", exception);
}
}