input: Write a python function to parse product details from a given HTML content using Scrapy framework.
  assert parse_product_details('<div class="product"><span class="title">Product 1</span><span class="price">$10</span><a href="/product1"></a></div>') == [{'title': 'Product 1', 'price': '$10', 'url': '/product1'}]
  assert parse_product_details('<div class="product"><span class="title">Product 2</span><span class="price">$20</span><a href="/product2"></a></div>') == [{'title': 'Product 2', 'price': '$20', 'url': '/product2'}]
  assert parse_product_details('<div class="product"><span class="title">Product 3</span><span class="price">$30</span><a href="/product3"></a></div>') == [{'title': 'Product 3', 'price': '$30', 'url': '/product3'}]
output: def parse_product_details(html):
      from scrapy import Selector
  
      sel = Selector(text=html)
      products = []
  
      for product in sel.css('div.product'):
          title = product.css('span.title::text').get()
          price = product.css('span.price::text').get()
          url = product.css('a::attr(href)').get()
          products.append({
              'title': title,
              'price': price,
              'url': url
          })
  
      return products