     cond do
       options[:help] or (0 < length invalid) ->
         usage
+      options[:benchmark] ->
+        benchmark
       true ->
         process(remaining, options)
     end

    strip = pOptions[:strip]
    pSetList
    |> Enum.map(&stringToSet(&1, token, character, strip))
    |> Enum.reduce([], &CustomSet.symmetricDifference/2)
    |> Enum.sort
    |> Enum.each(&IO.puts/1)
  end
end


    IO.puts("    -c          : operate on sets of characters instead of sets of strings")
    IO.puts("    --strip     : strip leading and trailing whitespace from set items")
    IO.puts("    -s          : strip leading and trailing whitespace from set items")
    IO.puts("    --benchmark : perform algorithm benchmark")
    IO.puts("    -b          : perform algorithm benchmark")
    IO.puts("    --help      : display this usage summary")
    IO.puts("    -?          : display this usage summary")
    IO.puts("Examples:")
