ENTSO-E connector throws error when fetching price data in read_series()-function

It seems like the API returns a XML-response containing not only one resolution but two (15min and 60min). However the connector concatenates the data of both resolutions together and tries to perform a resample which is not working because of the resulting duplicates in the index.

This is somehow not matched in the test cases because the mockup data only contains one resolution. I fetched the same data from the API as in the mockup today and it returns the additional 15min resolution: Price_sample_new.xml

Has the entsoe API changed? In this case it would be useful to introduce a resolution parameter to the read_series()-function.