Minor API polishment.
Minor API polishment.

The min, max, mean fields in Vec should be private
to avoid accidental accessing of fields without calling rollupstats
(since the fields are initialized lazily)

h2oai/h2o-2,h2oai/h2o,eg-zhang/h2o-2,100star/h2o,calvingit21/h2o-2,elkingtonmcb/h2o-2,rowhit/h2o-2,vbelakov/h2o,111t8e/h2o-2,111t8e/h2o-2,elkingtonmcb/h2o-2,rowhit/h2o-2,h2oai/h2o,elkingtonmcb/h2o-2,calvingit21/h2o-2,h2oai/h2o,calvingit21/h2o-2,h2oai/h2o-2,eg-zhang/h2o-2,100star/h2o,h2oai/h2o,rowhit/h2o-2,vbelakov/h2o,h2oai/h2o-2,111t8e/h2o-2,calvingit21/h2o-2,rowhit/h2o-2,100star/h2o,111t8e/h2o-2,eg-zhang/h2o-2,h2oai/h2o,vbelakov/h2o,rowhit/h2o-2,vbelakov/h2o,vbelakov/h2o,h2oai/h2o,h2oai/h2o-2,elkingtonmcb/h2o-2,h2oai/h2o-2,h2oai/h2o-2,111t8e/h2o-2,calvingit21/h2o-2,rowhit/h2o-2,rowhit/h2o-2,calvingit21/h2o-2,eg-zhang/h2o-2,100star/h2o,eg-zhang/h2o-2,eg-zhang/h2o-2,111t8e/h2o-2,h2oai/h2o-2,elkingtonmcb/h2o-2,h2oai/h2o-2,h2oai/h2o,elkingtonmcb/h2o-2,calvingit21/h2o-2,elkingtonmcb/h2o-2,eg-zhang/h2o-2,111t8e/h2o-2,h2oai/h2o,elkingtonmcb/h2o-2,calvingit21/h2o-2,100star/h2o,elkingtonmcb/h2o-2,eg-zhang/h2o-2,100star/h2o,111t8e/h2o-2,h2oai/h2o,rowhit/h2o-2,calvingit21/h2o-2,h2oai/h2o-2,vbelakov/h2o,100star/h2o,rowhit/h2o-2,vbelakov/h2o,vbelakov/h2o,100star/h2o,111t8e/h2o-2,h2oai/h2o-2,vbelakov/h2o,h2oai/h2o,100star/h2o,rowhit/h2o-2,eg-zhang/h2o-2,elkingtonmcb/h2o-2,calvingit21/h2o-2,eg-zhang/h2o-2,111t8e/h2o-2,vbelakov/h2o