anchor.diff:     stringr_1.0.0.tar.gz \
      knitr_1.13.tar.gz \
      yaml_2.1.13.tar.gz \
  -   Rcpp_0.12.5.tar.gz \
  +   Rcpp_0.12.6.tar.gz \
      htmltools_0.3.5.tar.gz \
      caTools_1.17.1.tar.gz \
      bitops_1.0-6.tar.gz \
  -   digest_0.6.9.tar.gz \
  -   mime_0.4.tar.gz
  +   digest_0.6.10.tar.gz \
  +   mime_0.5.tar.gz
   
   # dependency for R XML library
   RUN apt-get update && \
  
positive.code: 
  RUN rm \
     jsonlite_0.9.22.tar.gz \
     digest_0.6.9.tar.gz \
     memoise_1.0.0.tar.gz \
     whisker_0.3-2.tar.gz \
     bitops_1.0-6.tar.gz \
     RCurl_1.95-4.8.tar.gz \
     Rcpp_0.12.5.tar.gz \
     plyr_1.8.4.tar.gz \
     R6_2.1.2.tar.gz \
     mime_0.4.tar.gz \
     httr_1.2.0.tar.gz \
     rstudioapi_0.6.tar.gz \
     openssl_0.9.4.tar.gz \
  
negative.code: RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
     bitops_1.0-6.tar.gz \
     caTools_1.17.1.tar.gz \
     digest_0.6.10.tar.gz \
     Rcpp_0.12.6.tar.gz \
     htmltools_0.3.5.tar.gz \
     yaml_2.1.13.tar.gz \
     stringi_1.1.1.tar.gz \
     magrittr_1.5.tar.gz \
     mime_0.5.tar.gz \
     stringr_1.0.0.tar.gz \
     highr_0.6.tar.gz \
     formatR_1.4.tar.gz \
  