title: Crawlera middleware order to enable httpcache
body: <p>I want to not use the crawlera proxy service for pages that are already cached using the httpcache middleware (since I have a limit for the number of calls per month).</p>
  
  <p>I'm using the crawlera middleware, and enabling it using:</p>
  
  <pre><code>DOWNLOADER_MIDDLEWARES = {
  'scrapy_crawlera.CrawleraMiddleware': 610}
  </code></pre>
  
  <p>as recommended in the documentation (<a href="https://scrapy-crawlera.readthedocs.io/en/latest/" rel="nofollow noreferrer">https://scrapy-crawlera.readthedocs.io/en/latest/</a>).</p>
  
  <p>Though, after a crawl ends, I get: </p>
  
  <pre><code>    2017-04-23 00:14:24 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
  {'crawlera/request': 11,
   'crawlera/request/method/GET': 11,
   'crawlera/response': 11,
   'crawlera/response/status/200': 10,
   'crawlera/response/status/301': 1,
   'downloader/request_bytes': 3324,
   'downloader/request_count': 11,
   'downloader/request_method_count/GET': 11,
   'downloader/response_bytes': 1352925,
   'downloader/response_count': 11,
   'downloader/response_status_count/200': 10,
   'downloader/response_status_count/301': 1,
   'dupefilter/filtered': 6,
   'finish_reason': 'closespider_pagecount',
   'finish_time': datetime.datetime(2017, 4, 22, 22, 14, 24, 839013),
   'httpcache/hit': 11,
   'log_count/DEBUG': 12,
   'log_count/INFO': 9,
   'request_depth_max': 1,
   'response_received_count': 10,
   'scheduler/dequeued': 10,
   'scheduler/dequeued/memory': 10,
   'scheduler/enqueued': 23,
   'scheduler/enqueued/memory': 23,
   'start_time': datetime.datetime(2017, 4, 22, 22, 14, 24, 317893)}
  2017-04-23 00:14:24 [scrapy.core.engine] INFO: Spider closed (closespider_pagecount)
  </code></pre>
  
  <p>with </p>
  
  <pre><code>downloader/request_count': 11
  crawlera/request/method/GET': 11
  httpcache/hit': 11
  </code></pre>
  
  <p>So I'm not sure whether this calls went through the crawlera proxy service or not. I get the same results when I change the crawlera middleware order to be 901, 749, 751. </p>
  
  <p>Does anyone know what's going under the hood? Are the pages returned directly from the http cache without calling the crawlera server or not?</p>
  
  <p>Thanks!</p>