public function AddGlobalVariable(
        \Peg\Lib\Definitions\Element\GlobalVariable $global_variable, 
        $namespace = "\\"
    )
    {
        $this->CreateNamespace($namespace);
        
        $global_variable->header =& $this;
        $global_variable->namespace =& $this->namespaces[$namespace];

        $this->namespaces[$namespace]
            ->global_variables[$global_variable->name] = $global_variable
        ;
    }