fill data tree
   data event 0
   data event 100000
fill signal tree
   signal event 0
   signal event 100000
   signal event 200000
   signal event 300000
   signal event 400000
   signal event 500000
   signal event 600000
   signal event 700000
   signal event 800000
   signal event 900000
   signal event 1000000
   signal event 1100000
   signal event 1200000
   signal event 1300000
   signal event 1400000
   signal event 1500000
   signal event 1600000
   signal event 1700000
   signal event 1800000
   signal event 1900000
fill background tree
   background event 0
   background event 100000
   background event 200000
   background event 300000
   background event 400000
   background event 500000
   background event 600000
   background event 700000
   background event 800000
   background event 900000
   background event 1000000
   background event 1100000
   background event 1200000
   background event 1300000
   background event 1400000
   background event 1500000
   background event 1600000
   background event 1700000
   background event 1800000
   background event 1900000