anchor.diff:     XML_3.98-1.4.tar.gz \
      BH_1.60.0-2.tar.gz \
      xml2_1.0.0.tar.gz \
  -   curl_1.1.tar.gz \
  +   curl_1.2.tar.gz \
      rversions_1.0.3.tar.gz \
      git2r_0.15.0.tar.gz \
      devtools_1.12.0.tar.gz \
  
positive.code: RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
     openintro_1.4.tar.gz \
     assertthat_0.1.tar.gz \
     R6_2.1.2.tar.gz \
     magrittr_1.5.tar.gz \
     lazyeval_0.2.0.tar.gz \
     DBI_0.4-1.tar.gz \
  
negative.code:    RCurl_1.95-4.8.tar.gz \
     Rcpp_0.12.6.tar.gz \
     plyr_1.8.4.tar.gz \
     R6_2.1.3.tar.gz \
     mime_0.5.tar.gz \
     httr_1.2.1.tar.gz \
     rstudioapi_0.6.tar.gz \
  