anchor.diff:      https://mirrors.nics.utk.edu/cran/src/contrib/rex_1.1.2.tar.gz \
       https://mirrors.nics.utk.edu/cran/src/contrib/stringdist_0.9.5.1.tar.gz \
       https://mirrors.nics.utk.edu/cran/src/contrib/praise_1.0.0.tar.gz \
  +    https://mirrors.nics.utk.edu/cran/src/contrib/desc_1.2.0.tar.gz \
       https://mirrors.nics.utk.edu/cran/src/contrib/bench_1.0.1.tar.gz 
   
   RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
  
positive.code: 
  RUN rm \
      modelr_0.1.2.tar.gz \
      praise_1.0.0.tar.gz \
      rex_1.1.2.tar.gz \
      stringdist_0.9.5.1.tar.gz \
  
negative.code:     praise_1.0.0.tar.gz \
      testthat_2.0.0.tar.gz \
      lintr_1.0.2.tar.gz \
      desc_1.2.0.tar.gz \
      pkgbuild_1.0.0.tar.gz \
      pkgload_1.0.0.tar.gz \
      rcmdcheck_1.2.1.tar.gz \
  