anchor.diff:    pip install numpy
   
   # Build and install ninja.
  -RUN git clone https://github.com/martine/ninja.git && \
  +ARG NINJA_VERSION=v1.7.2
  +RUN git clone -b $NINJA_VERSION https://github.com/martine/ninja.git && \
     cd ninja && \
  -  git checkout $NINJA_VERSION && \
     ./configure.py --bootstrap && \
     mv ninja /usr/bin/ && \
     cd .. && \
     rm -rf ninja
   
   # Build and install googletest
  -RUN git clone https://github.com/google/googletest.git && \
  +ARG GTEST_VERSION=release-1.8.0
  +RUN git clone -b $GTEST_VERSION https://github.com/google/googletest.git && \
     mkdir googletest-build && \
     cd googletest-build && \
     cmake -DCMAKE_INSTALL_PREFIX:PATH=/opt/googletest ../googletest && \
  
positive.code: 
  # Build and install ParaView
  ARG PARAVIEW_VERSION=f38113aa2a2a7a7549e1aa5033b546586c07bb74
  RUN git clone --recursive git://github.com/kitware/paraview.git && \
    cd paraview && \
    git checkout $PARAVIEW_VERSION && \
    git submodule update && \
    cd .. && \
    mkdir paraview-build && \
  
negative.code:   cd .. && \
    rm -rf $QT_DIR
  
  # Build and install ITK
  ARG ITK_VERSION=v4.9.0
  RUN git clone -b $ITK_VERSION git://itk.org/ITK.git && \
    mkdir itk-build && \
    cd itk-build && \
    cmake -G Ninja -DCMAKE_BUILD_TYPE:STRING=Release \
  