anchor.diff:          cron \
           git \
           curl \
  +        zip \
  +        unzip \
           vim \
           nano \
           nodejs \
  
positive.code: 
  # Install "software-properties-common" (for the "add-apt-repository")
  RUN apt-get update && apt-get install -y \
      software-properties-common
  
  # Add the "PHP 7" ppa
  RUN add-apt-repository -y \
  
negative.code: RUN . ~/.bashrc
  
  # Clean up, to free some space
  RUN apt-get remove -y --purge software-properties-common \
      && apt-get -y autoremove \
      && apt-get clean \
      && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  WORKDIR /var/www/site