anchor.diff:      pip install -U --upgrade-strategy only-if-needed --no-cache-dir pillow==3.4.1 && \
       pip install -U --upgrade-strategy only-if-needed --no-cache-dir google-cloud-dataflow==2.0.0 && \
       pip install -U --upgrade-strategy only-if-needed --no-cache-dir tensorflow==1.2.1 && \
  +    pip install -U --upgrade-strategy only-if-needed --no-cache-dir python-snappy==0.5.1 && \
       find /usr/local/lib/python2.7 -type d -name tests | xargs rm -rf && \
   
   # Python 3
  
positive.code:     pip3 install -U --upgrade-strategy only-if-needed --no-cache-dir crcmod==1.7 && \
      pip3 install -U --upgrade-strategy only-if-needed --no-cache-dir pillow==3.4.1 && \
      pip3 install -U --upgrade-strategy only-if-needed --no-cache-dir tensorflow==1.2.1 && \
  # Install IPython related packages with no-deps, to ensure that we don't
  # Overwrite the python 2 version of jupyter with the python 3 version.
      pip3 install -U --upgrade-strategy only-if-needed --no-cache-dir ipywidgets==6.0.0 && \
  
negative.code:     apt-get update -y && \
      apt-get install --no-install-recommends -y -q python unzip ca-certificates build-essential \
      libatlas-base-dev liblapack-dev gfortran libpng-dev libfreetype6-dev libxft-dev libxml2-dev \
      libsnappy-dev python-dev python-setuptools python-zmq openssh-client wget curl git \
      pkg-config zip && \
      easy_install pip && \
      mkdir -p /tools && \
  
  