anchor.diff:     http://archive.linux.duke.edu/cran/src/contrib/cellranger_1.1.0.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/tidyr_0.5.1.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/googlesheets_0.2.1.tar.gz \
  +   http://archive.linux.duke.edu/cran/src/contrib/hms_0.2.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/readr_1.0.0.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/purrr_0.2.2.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/selectr_0.2-3.tar.gz \
  
positive.code:    cellranger_1.1.0.tar.gz \
     tidyr_0.5.1.tar.gz \
     googlesheets_0.2.1.tar.gz \
     readr_1.0.0.tar.gz \
     purrr_0.2.2.tar.gz \
     selectr_0.2-3.tar.gz \
  
negative.code:    rematch_1.0.1.tar.gz \
     cellranger_1.1.0.tar.gz \
     tidyr_0.5.1.tar.gz \
     hms_0.2.tar.gz \
     readr_1.0.0.tar.gz \
     purrr_0.2.2.tar.gz \
     googlesheets_0.2.1.tar.gz \
  