anchor.diff:      git reset --hard $MAGENTA_MASTER_REF
   WORKDIR /magenta
   RUN bazel build //magenta/... && bazel test //magenta/...
  -
  -# Required to build the pip package
  -RUN pip install pretty_midi
   
   RUN bazel build magenta/tools/pip:build_pip_package && \
       bazel-bin/magenta/tools/pip/build_pip_package /tmp/magenta_pkg && \
  
positive.code: 
  # Download and build Magenta.
  
  ENV MAGENTA_MASTER_REF v0.1.5
  
  WORKDIR /
  RUN git clone https://github.com/tensorflow/magenta.git && \
  
negative.code: ADD http://download.magenta.tensorflow.org/models/basic_rnn.mag /magenta-models/
  ADD http://download.magenta.tensorflow.org/models/multistyle-pastiche-generator-monet.ckpt /magenta-models/
  ADD http://download.magenta.tensorflow.org/models/multistyle-pastiche-generator-varied.ckpt /magenta-models/
  ADD http://download.magenta.tensorflow.org/models/rl_tuner_note_rnn.ckpt /magenta-models/
  
  # /magenta-data should be mapped to the host on startup.
  RUN mkdir /magenta-data
  