anchor.diff:  # install sparklyr so we can do Spark via Livy
   RUN DEBIAN_FRONTEND=noninteractive wget \
      https://mirrors.nics.utk.edu/cran/src/contrib/config_0.3.tar.gz \
  -   https://mirrors.nics.utk.edu/cran/src/contrib/dbplyr_1.2.1.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/dbplyr_1.2.2.tar.gz \
      https://mirrors.nics.utk.edu/cran/src/contrib/rappdirs_0.3.1.tar.gz \
  -   https://mirrors.nics.utk.edu/cran/src/contrib/sparklyr_0.7.0.tar.gz
  +   https://mirrors.nics.utk.edu/cran/src/contrib/sparklyr_0.8.4.tar.gz
      
   RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
      config_0.3.tar.gz \
  -   dbplyr_1.2.1.tar.gz \
  +   dbplyr_1.2.2.tar.gz \
      rappdirs_0.3.1.tar.gz \
  -   sparklyr_0.7.0.tar.gz
  +   sparklyr_0.8.4.tar.gz
      
   RUN rm \
     config_0.3.tar.gz \
  -  dbplyr_1.2.1.tar.gz \
  +  dbplyr_1.2.2.tar.gz \
     rappdirs_0.3.1.tar.gz \
  -  sparklyr_0.7.0.tar.gz
  +  sparklyr_0.8.4.tar.gz
   
   
   # some more TeX so that papaja can be installed and students can create APA templates in Rmarkdown
  
positive.code:    progress_1.2.0.tar.gz \
     GGally_1.4.0.tar.gz \
     mosaicCore_0.6.0.tar.gz \
     ggformula_0.9.0.tar.gz \
     mosaic_1.4.0.tar.gz 
  
  
negative.code:    progress_1.2.0.tar.gz \
     GGally_1.4.0.tar.gz \
     mosaicCore_0.6.0.tar.gz \
     ggstance_0.3.1.tar.gz \
     ggformula_0.9.0.tar.gz \
     mosaic_1.4.0.tar.gz 
  
  