anchor.diff:  # Enable non-free archive for `unrar`.
   # RUN echo "deb http://http.us.debian.org/debian stretch non-free" >/etc/apt/sources.list.d/nonfree.list
   RUN apt-get -qq -y update \
  -    && apt-get -q -y install build-essential locales ca-certificates \
  +    && apt-get -qq -y install build-essential locales ca-certificates \
           # python deps (mostly to install their dependencies)
           python3-pip python3-dev python3-pil \
           # tesseract
  
positive.code: ENV DEBIAN_FRONTEND noninteractive
  
  RUN apt-get -qq -y update \
      && apt-get -q -y upgrade \
      && apt-get -q -y install \
          tesseract-ocr-eng \
          tesseract-ocr-swa \
          tesseract-ocr-swe \
  
negative.code: 
  RUN pip3 install --no-cache-dir -q -U pip setuptools six wheel nose coverage
  COPY requirements.txt /tmp/
  RUN pip3 install --no-cache-dir -q -r /tmp/requirements.txt
  
  # Install spaCy and link models to three-letter language codes
  RUN python3 -m spacy download xx_ent_wiki_sm \
  