xgrove_0.1-7 2023-09-12  - Changes according to CRAN newbei check: reference added to description, vlaue added to .Rd files plot.sgtree, plot.xgrove, upsilon  
xgrove_0.1-6 2023-09-11  - Title field changed to title case according to note from r-winbuilder.
xgrove_0.1-5 2023-09-08  - ln.1 added according to 'vo visible binding' note referring to ln.123 / group_by
xgrove_0.1-4 2023-09-07  - Arguments shrink = 1, b.frac = 1 added to xgrove() in order to change defaults of gbm() call.
xgrove_0.1-3 2023-05-15  - Function sgtree() added to compute surrogate trees.