anchor.diff:  
   RUN apt-get update \
     && apt-get install -y --no-install-recommends \
  -    build-essential \
  -    pkg-config \
  -    libffi-dev \
  -    libssl-dev \
       curl \
       git \
  -    openssh-client \
       # runtime packages
       unzip \
       php-pear \
       python3-pip \
       # Java
  -    openjdk-8-jdk \
  +    openjdk-8-jdk-headless \
       # NodeJS
       # This installs Node 4 on Ubuntu 16.04.
       nodejs \
  
positive.code:     libtool \
      autotools-dev \
      automake \
      # Used to create Python doc
      pandoc \
      # .NET dependencies
  
negative.code:     && ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet
  
  # Install googleapis.
  RUN git clone --single-branch https://github.com/googleapis/googleapis \
    && cd googleapis \
    && git checkout $GOOGLEAPIS_HASH \
    && cd .. \
    && rm -rf /googleapis/.git/
  
  # Install toolkit.
  RUN git clone --single-branch https://github.com/googleapis/gapic-generator toolkit \
    && cd toolkit/ \
    && git checkout $GAPIC_GENERATOR_HASH \
    && ./gradlew fatJar createToolPaths \
  