anchor.diff:  ENV LANGUAGE ja_JP.UTF-8
   ENV LC_ALL ja_JP.UTF-8
   
  -USER root
   # Cleaning
  -RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  +RUN sudo apt clean && \
  +    sudo rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
positive.code: # ------------------
  # Install Basic softwares
  # ------------------
  RUN sudo apt update && \
      sudo apt install -y locales && \
      sudo localedef -f UTF-8 -i ja_JP ja_JP.utf8 && \
      sudo apt install -y git vim curl make netcat libreadline-dev nkf bc expect tree inotify-tools \
      # In order to develop debian package (Ref: http://www.rain.hyarc.nagoya-u.ac.jp/~satoki/main/Linux/configure/make_deb.html).
  
negative.code: FROM ubuntu:16.04
  MAINTAINER Yamada, Yasuhiro <greengregson@gmail.com>
  ENV DEBFULLNAME="Yamada, Yasuhiro" DEBEMAIL=greengregson@gmail.com
  
  # Prepare sudo
  RUN apt update && apt install -y sudo
  
  # Add a non-root user
  RUN useradd -m -d /home/docker -s /bin/bash docker && \
  