anchor.diff:  RUN \
       apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 379CE192D401AB61 && \
       apt-get update && \
  -    apt-get install --yes --force-yes portal && \
  +    apt-get install --yes --allow-unauthenticated portal && \
       apt-get clean && \
       rm --force --recursive --verbose /tmp/artifacts
   
  
positive.code: RUN \
      apt-get update && \
      apt-get dist-upgrade --yes && \
      apt-get install --yes --force-yes --no-install-recommends \
          ca-certificates \
          libpq5 \
          python2.7 && \
  
negative.code: FROM debian:stretch
  
  ENV \
      DEBIAN_FRONTEND="noninteractive" \
  