Package check result: NOTE

Check: examples, Result: NOTE
  Examples with CPU (user + system) or elapsed time > 5s
                   user system elapsed
  explain_xgboost 8.642  0.177    1.82
  Examples with CPU time > 2.5 times elapsed time
                   user system elapsed ratio
  explain_xgboost 8.642  0.177    1.82 4.846

No changes to worse in reverse depends.