Using relations for setting in Zend_Db_Table_Row

$contentModel = new Content();
$categoryModel = new Category();

$category = $categoryModel->createRow();
$category->setName('Name Category 4');

$content = $contentModel->createRow();
$content->setTitle('Title 4');

$content->setCategory($category);
$content->save();

$contentModel = new Content();
$categoryModel = new Category();

$category = $categoryModel->createRow();
$category->setName('Name Category 4');

$content = $contentModel->createRow();
$content->setTitle('Title 4');

// saving populates the primary key field in the Row object
$category->save();

$content->setCategory($category->category_id);
$content->save();

protected $_rowClass = 'Db_Table_Row';

public function __get($key)
{
	$inflector = new Zend_Filter_Word_UnderscoreToCamelCase();

	$method = 'get' . $inflector->filter($key);

	if(method_exists($this, $method)) {
		return $this->{$method}();
	}

	return parent::__get($key);
}

public function __set($key, $value)
{
	$inflector = new Zend_Filter_Word_UnderscoreToCamelCase();

	$method = 'set' . $inflector->filter($key);

	if(method_exists($this, $method))
		return $this->{$method}($value);

	return parent::__set($key, $value);
}

public function setCategory($value)
{
     $this->category_id = $value->category_id;
}