anchor.diff:  \n\
       location ~ \.php$ {\n\
           include snippets/fastcgi-php.conf;\n\
  -        fastcgi_pass unix:/run/php/php7.0-fpm.sock;\n\
  +        fastcgi_pass unix:/run/php/php7.3-fpm.sock;\n\
       }\n\
   }'\
   > /etc/nginx/sites-enabled/default
  
positive.code: 
  # Add php-fpm daemon.
  RUN mkdir /etc/service/php-fpm
  RUN echo '#!/usr/bin/env bash\nservice php7.0-fpm start' > /etc/service/php-fpm/run
  RUN chmod +x /etc/service/php-fpm/run
  
  # Add homepage.
  
negative.code: RUN echo "daemon off;" >> /etc/nginx/nginx.conf
  
  # Install PHP.
  RUN add-apt-repository ppa:ondrej/php
  # Avoid "debconf: unable to initialize frontend: Dialog" by using DEBIAN_FRONTEND=noninteractive before install command.
  RUN DEBIAN_FRONTEND=noninteractive apt-get -y install php7.3-fpm
  RUN echo "php version: $(php -v)"
  
  # Add nginx daemon.
  