+sub convertible_to_filter {
+ my ($class, $key, $unit_name, $prefix) = @_;
+
+ return () unless $unit_name;
+
+ $prefix //= '';
+
+ my $unit = $class->find_by(name => $unit_name);
+ if (!$unit) {
+ $::lxdebug->warn("Unit manager: No unit with name $unit_name");
+ return ();
+ }
+
+ return ("${prefix}name" => [ map { $_->name } @{ $unit->convertible_units } ]);
+}
+