protected function processArgumentService(Element $arg) {
		$definition = new stdClass();
		$definition->type = 'service';
		
		if (! isset($arg->id)) {
			throw new InvalidConfig('Definition of an argument type "service" must contain the "id" attribute', null, null, $arg);
		}
		
		$definition->id = trim($arg->id);
		
		$content = $arg->getContent();
			
		if (! empty($content)) {
			$this->processDefinitionParameters($content, $definition);
		}
		
		return $definition;
	}