$msg = sprintf('You have requested a non-existent service "%s".', $id);
} else {
$msg = sprintf('The service "%s" has a dependency on a non-existent service "%s".', $sourceId, $id);
$msg = sprintf('You have requested a non-existent service "%s".', $id);
} else {
$msg = sprintf('The service "%s" has a dependency on a non-existent service "%s".', $sourceId, $id);