input: Write a python function to extract titles, prices, and descriptions from an HTML response using scrapy.
  assert extract_info(response1) == [{'title': 'Item 1', 'price': '$10', 'description': 'Description 1'}, {'title': 'Item 2', 'price': '$20', 'description': 'Description 2'}]
  assert extract_info(response2) == [{'title': 'Product A', 'price': '$15', 'description': 'Description A'}, {'title': 'Product B', 'price': '$25', 'description': 'Description B'}]
  assert extract_info(response3) == [{'title': 'Service X', 'price': '$30', 'description': 'Description X'}, {'title': 'Service Y', 'price': '$40', 'description': 'Description Y'}]
output: def extract_info(response):
      items = []
      for product in response.xpath('//div[@class="product"]'):
          title = product.xpath('.//h2/text()').get()
          price = product.xpath('.//span[@class="price"]/text()').get()
          description = product.xpath('.//p[@class="description"]/text()').get()
          items.append({
              'title': title,
              'price': price,
              'description': description
          })
      return items