Issue with UpsupportedOperationException in SparkTrainingDataFinder during Databricks example label saving section

Hello, I'm working through the Databricks example and I have run into an issue in the 'Saving all the labels provided by the user' section. First I had to refactor the code to extract the pair id from the html pair content, the code in the example did not work. This was a minor issue that was easily fixed. However now I am getting an UpsupportedOperationException error related to zingg.spark.core.executor.SparkTrainingDataFinder.