anchor.diff:  
   # programs needed for building
   RUN apt-get update && apt-get install -y \
  -  build-essential \
  -  curl \
  -  sudo \
  -  unzip \
  -  wget \
  -  gnupg2 \
  -  apt-utils \
  -  software-properties-common \
  -  bzr
  +    build-essential \
  +    curl \
  +    sudo \
  +    unzip \
  +    wget \
  +    gnupg2 \
  +    apt-utils \
  +    software-properties-common \
  +    bzr
   
   RUN add-apt-repository ppa:git-core/ppa && apt-get update && apt-get install -y git
   
  
positive.code:     && tar xf flutter_linux_2.8.1-stable.tar.xz \
      && mv flutter ${FLUTTER_HOME} \
      && rm flutter_linux_2.8.1-stable.tar.xz
          
  ENV PATH=$PATH:${FLUTTER_HOME}/bin:${FLUTTER_HOME}/bin/cache/dart-sdk/bin
  RUN flutter doctor -v \
      && flutter update-packages \
  
negative.code: 
  # install yarn
  RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add - && \
      echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list && \
      apt-get update && \
      apt-get install yarn
  
  # install bower
  RUN npm install -g bower && \
      echo '{ "allow_root": true }' > /root/.bowerrc
  
  # install pnpm
  RUN curl -fsSL "https://github.com/pnpm/pnpm/releases/latest/download/pnpm-linuxstatic-x64" -o /bin/pnpm; chmod +x /usr/local/bin/pnpm;
  
  # install jdk 12
  RUN curl -L -o openjdk12.tar.gz https://download.java.net/java/GA/jdk12.0.2/e482c34c86bd4bf8b56c0b35558996b9/10/GPL/openjdk-12.0.2_linux-x64_bin.tar.gz && \
  