+ croak 'Unknown "type" parameter' unless $params{type} =~ m{^(?:customer|vendor)$};
+ croak 'Unknown value class' if $value && ref($value) && (ref($value) !~ m{^SL::DB::(?:Customer|Vendor)$});
+
+ if ($value && !ref $value) {
+ my $class = $params{type} eq 'customer' ? 'SL::DB::Manager::Customer' : 'SL::DB::Manager::Vendor';
+ $value = $class->find_by(id => $value);
+ }
+