Axlsx: Line Chart without axis labels

axlsx.rb

    require 'axlsx'
    p = Axlsx::Package.new
    p.workbook.add_worksheet(:name => "Line Chart") do |sheet|
      sheet.add_row ['1', '2', '3', '4']
      sheet.add_row [1, 2, 3, '=sum(A2:C2)']
      sheet.add_chart(Axlsx::Line3DChart, :start_at => [0,2], :end_at => [5, 15], :title => "Chart") do |chart|
        chart.add_series :data => sheet["A2:D2"], :labels => sheet["A1:D1"]

        chart.serAxis.tick_lbl_pos = :none

        chart.catAxis.tick_lbl_pos = :none

        chart.valAxis.tick_lbl_pos = :none

      end
     end
     p.serialize 'line_chart.xlsx'