public function registerClass($alias, $class)
    {
        $classSymbol = new ClassSymbol($alias, $class);
        $this->classes[$alias] = $classSymbol;
        $aliasNamespace = $classSymbol->getAliasNamespace();
        if (!in_array($aliasNamespace, $this->aliasNamespaces, true)) {
            $this->aliasNamespaces[] = $aliasNamespace;
        }
    }