Test environments local Windows 10 v.1809 x64, R 3.5.3 ubuntu (on travis-ci) Mac OS X (on travis-ci) 10.13.3, R 3.6.1 local Mac OS X High Sierra 10.13.6, R 3.6.1 ##R CMD check results There were no ERRORs or WARNINGs or NOTEs. Downstream dependencies