breakdown for classifications with filter not working

[SaturnFromTitan]

I want to automate a classification process. Therefore I need a report that lists all unlabeled keys of a selected classification. In the UI I'd break the "Unspecified" line of the classification down by the original variable. Here's an example of what I tried for the product variable:

report = suite.report\
    .element("product", classification="Product Name", selected=["::unspecified::"])\
    .breakdown("product", top=50000)\
    .metric("pageviews")\
    .range(start="2000-01-01", stop="2017-09-30")\
    .run().dataframe

But this only returns

pageviews      product | Product Name
9999999        ::unspecified::

As you can see the breakdown is completely missing. In fact I receive the exact same report if I remove the .breakdown() line in my report request. Is this a bug, or is my report request flawed?

I'd except/want a report like this:

pageviews      product | Product Name      product
10             ::unspecified::             10001
15             ::unspecified::             10002
12             ::unspecified::             10003
...

[SaturnFromTitan]

I dug a little deeper and figured out the problem arises from the filter. The "selected=["::unspecified::"]" criteria of the Product Name element is populated to the breakdown as well because it refers to the same element.
A quick fix is to skip the validation using disable_validation=True.

[SaturnFromTitan]

For everybody who faces similar problems: Try my new branch of this repository - https://github.com/SaturnFromTitan/adobe_analytics

The API works a bit differently, but it's more robust and supports more features - especially data warehouse requests.