anchor.diff:          echo "Adding contents..."
           for item in $contents; do
             echo "Adding $item"
  -          rsync -ak --chown=0:0 $item/ layer/
  +          rsync -a${if keepContentsDirlinks then "K" else "k"} --chown=0:0 $item/ layer/
           done
         else
           echo "No contents to add to layer."
  
positive.code:         if runAsRoot == null
          then mkPureLayer {
            name = baseName;
            inherit baseJson contents extraCommands;
          } else mkRootLayer {
            name = baseName;
            inherit baseJson fromImage fromImageName fromImageTag
                    contents runAsRoot diskSize extraCommands;
          };
        result = runCommand "docker-image-${baseName}.tar.gz" {
          buildInputs = [ jshon pigz coreutils findutils ];
  
negative.code:         echo "Adding contents..."
          for item in ${toString contents}; do
            echo "Adding $item..."
            rsync -a${if keepContentsDirlinks then "K" else "k"} --chown=0:0 $item/ layer/
          done
        '';
  
  