title: scrapy single spider to pass multiple item classes to pipeline
body: <p>I am new to scrapy. In items.py, I declare 2 ItemClass called ItemClass1 and ItemClass2. A spider method parseUrl get the html and scrape data and put into lists for respective Item Classes.</p>
  
  <pre><code>e.g:
  C1Items = []
  C1Item = ItemClass1()
  #scrape data
  C1Items.append(C1Item)
  ...
  C2Items = []
  C2Item = ItemClass2()
  #scrape data
  C2Items.append(C2Item)
  ...
  </code></pre>
  
  <p>finally: C1Items and C2Items contain required data. </p>
  
  <pre><code>return C1Items #will pass ItemClass1 data to pipeline
  return C2Items #will pass ItemClass2 data to pipeline
  </code></pre>
  
  <p>Could you please advise what is the best way to pass both C1Items, C2Items to pipeline. </p>