title: 'module' object has no attribute 'ImageRequestOptions'
body: <p>I tried to download a Tableau Workbook in as an image png-format and uses the sample from GitHub: <a href="https://github.com/tableau/server-client-python/blob/master/samples/download_view_image.py" rel="nofollow noreferrer">https://github.com/tableau/server-client-python/blob/master/samples/download_view_image.py</a> using the tableauserverclient. But i get the error from above. I think I may have to Import something more, I only importet the tableauserverclient. Does anybody has an idea what I do wrong?</p>
  
  <p>relevant Code:</p>
  
  <pre><code>import argparse
  import getpass
  import logging
  
  import tableauserverclient as TSC
  </code></pre>
  
  <h1>Step 3: Query the image endpoint and save the image to the specified location</h1>
  
  <pre><code>image_req_option = TSC.ImageRequestOptions    (imageresolution=TSC.ImageRequestOptions.Resolution.High)
      server.views.populate_image(view_item, image_req_option)
  with open(args.filepath, "wb") as image_file:
      image_file.write(view_item.image)
  
  print("View image saved to {0}".format(args.filepath))`
  </code></pre>
  
  <p>Full Error Message:</p>
  
  <pre><code>Traceback (most recent call last):
    File "pdf2.test.py", line 69, in &lt;module&gt;
      main()
    File "pdf2.test.py", line 59, in main
      image_req_option = TSC.ImageRequestOptions(imageresolution=TSC.ImageRequestO                                                                  ptions.Resolution.High)
  AttributeError: 'module' object has no attribute 'ImageRequestOptions'
  </code></pre>