private function registerAliases()
{
foreach ($this->serviceAliases as $alias => $concrete) {
$ex = null;
try {
$this->container->alias($alias, $concrete);
} catch (Error $ex) {
} catch (Exception $ex) {
}
if ($ex !== null) {
throw new ExecutionException("Alias [{$alias}] could not have be registered.", $ex);
}
}
}