anchor.diff:  RUN jupyter nbextension enable --py widgetsnbextension --sys-prefix
   
   #====================================================================================
  -# Ferret Datasets installation
  -
  -USER root
  -WORKDIR /opt
  -RUN git clone https://github.com/NOAA-PMEL/FerretDatasets fer_dsets
  -
  -#====================================================================================
   # fast installation
   
   USER root
  
positive.code: RUN git clone https://github.com/PBrockmann/fast
  
  #====================================================================================
  ENV FER_DIR="/opt/conda/pkgs/pyferret-7.5.0-py37hb511868_2/"
  ENV FER_DSETS="/opt/fer_dsets"
  
  ENV FER_DATA=". ${FER_DSETS}/data ${FER_DIR}/contrib /opt/fast"
  ENV FER_DESCR=". ${FER_DSETS}/descr"
  ENV FER_GRIDS=". ${FER_DSETS}/grids"
  ENV FER_GO=". ${FER_DIR}/go ${FER_DIR}/examples ${FER_DIR}/contrib /opt/fast"
  ENV FER_PALETTE=". /${FER_DIR}/ppl /opt/fast"
  ENV FER_FONTS="${FER_DIR}/ppl/fonts"
  ENV PYFER_EXTERNAL_FUNCTIONS="${FER_DIR}/ext_func/pylibs"
  
  ENV PATH="${FER_DIR}/bin:/opt/fast:${PATH}"
  
  
negative.code: #====================================================================================
  USER root
  
  RUN conda create -n FERRET -c conda-forge pyferret ferret_datasets --yes
  RUN conda install -c r rpy2
  
  RUN pip install --no-cache-dir notebook==6.*
  