anchor.diff:      php7-json \
       php7-zlib \
       php7-xml \
  +    php7-xmlreader \
  +    php7-xmlwriter \
       php7-pdo \
       php7-phar \
       php7-openssl \
  
positive.code: FROM alpine:edge
  
  RUN echo 'http://dl-4.alpinelinux.org/alpine/edge/testing' >> /etc/apk/repositories \
      && apk update \
      && apk add --no-cache --update \
      bash \
  
negative.code:     php7-xmlreader \
      php7-gettext \
      php7-tokenizer \
      php7-zip \
      openssh-client \
      git \
      curl \
  