code: public void preSearch(Instances data) throws Exception {
      m_Cache        = new PerformanceCache();
      m_Performances = new Vector<Performance>();
      m_Trace        = new ArrayList<Entry<Integer, Performance>>();
  
      m_Owner.getGenerator().reset();
      m_Space = m_Owner.getGenerator().getSpace();
    }
docs: Called before the search is executed.
  <br>
  Default implementation only initializes the trace.
  
  @param data	the dataset to use
  @throws Exception	if search fails