Decision Tree pruning option not functioning

[adeokar]

The pruning option in the "Decision Tree" operator seems to be non-functional. Regardless of whether the pruning option is checked or not, the tree obtained is the same. Also, varying the confidence values (when the pruning option is checked) does not have any effect.

For testing - pre-pruning was turned off, with max depth set to -1; different criterion options (gain ratio, information gain, and gini index) were tried.