Weka is a collection of machine learning algorithms for data mining tasks. The algorithms can either be applied directly to a dataset or called from your own Java code. Weka contains tools for data pre-processing, classification, regression, clustering, association rules, and visualization. It is also well-suited for developing new machine learning schemes.
To use this method set Evaluator to this class (or its object) and then you can use any of the search methods like bestFirst, randomSearch, greedyStepwise, geneticSearch, and randomSearch.
Source: Weka FAQ