public function testAddToCart()
{
$add_to_cart = array('content_id' => 1, 'price' => 35);
$cart_add = update_cart($add_to_cart);
$this->assertEquals(isset($cart_add['success']), true);
$this->assertEquals(isset($cart_add['product']), true);
$this->assertEquals($cart_add['product']['price'], 35);
}