anchor.diff:             xenial \
              edge" && \
       apt-get -y update && \
  -    apt-get -y install docker-ce=17.12.0~ce-0~ubuntu
  +    apt-get -y install docker-ce=17.12.0~ce-0~ubuntu && \
  +    rm -rf /var/lib/apt/lists/*
   
   COPY --from=golang:1.10 /usr/local/go /usr/local/go
   ENV PATH /usr/local/go/bin:/go/bin:$PATH
  
positive.code: 
  ENV ASCIIDOCTOR_VERSION=1.5.7.1
  ENV ASCIIDOCTOR_PDF_VERSION=1.5.0.alpha.16
  RUN apt-get install --no-install-recommends --no-install-suggests -y \
          ca-certificates \
          curl \
          build-essential \
  
negative.code:  tar -zxvf google-cloud-sdk-${CLOUD_SDK_VERSION}-linux-x86_64.tar.gz && \
      CLOUDSDK_PYTHON="python2.7" /google-cloud-sdk/install.sh --usage-reporting=false \
          --bash-completion=false \
          --disable-installation-options && \
    rm -rf google-cloud-sdk-*.tar.gz
  ENV PATH=$PATH:/google-cloud-sdk/bin
  RUN /google-cloud-sdk/bin/gcloud auth configure-docker
  
  