the importance filter by default uses the "featureless" learner by default, which makes the filter basically useless. There are likely very few cases in which the user wants to initialize the importance filter with the featureless learner. Therefore, the learner should not have a default; when constructing the importance filter without providing a learner, an error should be thrown instead.
the importance filter by default uses the "featureless" learner by default, which makes the filter basically useless. There are likely very few cases in which the user wants to initialize the importance filter with the featureless learner. Therefore, the learner should not have a default; when constructing the importance filter without providing a learner, an error should be thrown instead.