anchor.diff:  # Yarn
   RUN bash -lc "curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -" && \
       bash -lc "echo 'deb https://dl.yarnpkg.com/debian/ stable main' | tee /etc/apt/sources.list.d/yarn.list" && \
  -    apt-get install -y apt-transport-https
  +    apt-fast install -y apt-transport-https
   
  -RUN apt-get update && apt-get install --no-install-recommends -y yarn
  +RUN apt-fast update && apt-fast install --no-install-recommends -y yarn
  +
  +RUN \
  +	apt-fast autoremove -y && \
  +	apt-fast autoclean && \
  +	rm -rf /var/lib/apt/lists/*
  +
   RUN /bin/bash -lc 'npm install -g yarn'
   
   # RUN yarn config set registry https://registry.npm.taobao.org
  
positive.code: WORKDIR /root
  
  # update
  RUN apt-get update && \
      apt-get upgrade -y && \
      apt-get autoremove -y
  
  RUN apt-get install -y make g++
  
  # nvm
  ENV NVM_VERSION 0.33.11
  
negative.code:     # echo ". ~/.config/fish/nvm-wrapper/nvm.fish" >> ~/.config/fish/config.fish
  
  # npm
  ENV NODE_VERSION 11.2.0
  RUN cp -f ~/.nvm/nvm.sh ~/.nvm/nvm-tmp.sh && \
      echo "nvm install v$NODE_VERSION" >> ~/.nvm/nvm-tmp.sh && \
      echo "nvm alias 10 $NODE_VERSION" >> ~/.nvm/nvm-tmp.sh && \
  