things being printed are like:
[21:21:33] Tree method is selected to be ‘hist’, which uses a single updater grow_fast_histmaker.
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 270 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 396 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 488 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 584 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 608 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 680 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 830 extra nodes, 0 pruned nodes, max_depth=12
[21:21:33] /workspace/src/tree/updater_prune.cc:74: tree pruning end, 1 roots, 880 extra nodes, 0 pruned nodes, max_depth=12
…
what are those? how to turn it off?