anchor.diff:  
   # define proxy environment variables to build image
   # if environment requires
  -#ENV http_proxy 'http://<proxy server>:<port>'
  -#ENV https_proxy 'http://<proxy server>:<port>'
  -#ENV ftp_proxy 'http://<proxy server>:<port>'
  -#ENV socks_proxy 'socks://<proxy server>:<port>'
  -#ENV no_proxy 'localhost,127.0.0.1,.<example.com>'
  +#ENV http_proxy='http://<proxy server>:<port>'
  +#ENV https_proxy='http://<proxy server>:<port>'
  +#ENV ftp_proxy='http://<proxy server>:<port>'
  +#ENV socks_proxy='socks://<proxy server>:<port>'
  +#ENV no_proxy='localhost,127.0.0.1,.<example.com>'
   
   # create apt proxy
   #RUN echo 'Acquire::http::Proxy "<proxy server>";' >>/etc/apt/apt.conf.d/20proxy
  
positive.code:     && apt-get autoremove \
      && apt-get clean
  
  
  # need to specify path to Ixia client library and
  # copy ixia files where X.XX is Ixia version
  
negative.code: ' > /root/requirements.txt && pip install --upgrade -r /root/requirements.txt && rm /root/requirements.txt && rm -rf /root/.cache/pip
  
  
  ARG TAF_ROOT=/root/taf
  # copy TAF repo to docker image
  COPY /  $TAF_ROOT/
  