anchor.diff:     https://archive.linux.duke.edu/cran/src/contrib/askpass_1.1.tar.gz \
      https://archive.linux.duke.edu/cran/src/contrib/openssl_1.2.2.tar.gz \
      https://archive.linux.duke.edu/cran/src/contrib/brew_1.0-6.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/magrittr_1.5.tar.gz \
      https://archive.linux.duke.edu/cran/src/contrib/Archive/roxygen2/roxygen2_5.0.1.tar.gz \
      https://archive.linux.duke.edu/cran/src/contrib/fs_1.2.7.tar.gz \
      https://archive.linux.duke.edu/cran/src/contrib/gh_1.0.1.tar.gz \
  
positive.code: # libraries Eric Green wanted
  RUN DEBIAN_FRONTEND=noninteractive wget \
     https://archive.linux.duke.edu/cran/src/contrib/lubridate_1.7.4.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/lazyeval_0.2.1.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/utf8_1.1.4.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/fansi_0.3.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/pillar_1.3.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/tibble_1.4.2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/ggplot2_3.0.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/RColorBrewer_1.1-2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/dichromat_2.0-0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/colorspace_1.3-2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/munsell_0.5.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/labeling_0.3.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/viridisLite_0.3.0.tar.gz \
  
negative.code: RUN rm \
     openintro_1.7.1.tar.gz \
     assertthat_0.2.0.tar.gz \
     DBI_1.0.0.tar.gz \
     bindr_0.1.1.tar.gz \
     bindrcpp_0.2.2.tar.gz \
     pkgconfig_2.0.2.tar.gz \
  