text: Title: XGBOD model file is too large
  Body: Hello!
  I spent an hour on my data set training an XGBOD model, and it worked well on the test set, but after saving the model file with PICKLE, I found that the file size was 1.2G! 
  Is there a way to reduce the size of the model file ? 
  (the size of my data set is (30412, 86))