public object Assign(ITenant tenant, TDoc document, out bool assigned)
{
var original = _getter != null?_getter(document) : default(TId);
var id = _generator.Assign(tenant, original, out assigned);
if (assigned)
{
if (_setter == null)
{
throw new InvalidOperationException($"The identity of {typeof(TDoc)} cannot be assigned");
}
_setter(document, id);
}
return(id);
}
