i am trying to understand how ml persists pipelines. it seems a SparkSession or SparkContext is needed for this, to write to hdfs.
MLWriter and MLReader both extend BaseReadWrite to have access to a SparkSession. but this is where it gets confusing... the only way to set the SparkSession seems to be in BaseReadWrite: def session(sparkSession: SparkSession): this.type and i can find no place this is actually used, except for in one unit test: org.apache.spark.ml.util.JavaDefaultReadWriteSuite i confirmed it is not used by simply adding a line inside that method that throws an error, and all unit tests pass except for JavaDefaultReadWriteSuite. how is the sparkSession set? thanks! koert