  </li>
<li>  You can fill the TEfficiency object by calling the <a href="http://root.cern.ch/root/html/TEfficiency.html#TEfficiency:Fill">Fill(Bool_t bPassed,Double_t x,Double_t y,Double_t z)</a> method.
   The boolean flag "bPassed" indicates whether the current event is a good
   (both histograms are filled) or not (only <a href="http://root.cern.ch/root/html/TEfficiency.html#TEfficiency:fTotalHistogram">fTotalHistogram</a> is filled).
   The variables x,y and z determine the bin which is filled. For low