def load_default_styles
      @numFmts = SimpleTypedList.new NumFmt, 'numFmts'
      @numFmts << NumFmt.new(:numFmtId => NUM_FMT_YYYYMMDD, :formatCode=> "yyyy/mm/dd")
      @numFmts << NumFmt.new(:numFmtId => NUM_FMT_YYYYMMDDHHMMSS, :formatCode=> "yyyy/mm/dd hh:mm:ss")

      @numFmts.lock

      @fonts = SimpleTypedList.new Font, 'fonts'
      @fonts << Font.new(:name => "Arial", :sz => 11, :family=>1)
      @fonts.lock

      @fills = SimpleTypedList.new Fill, 'fills'
      @fills << Fill.new(Axlsx::PatternFill.new(:patternType=>:none))
      @fills << Fill.new(Axlsx::PatternFill.new(:patternType=>:gray125))
      @fills.lock

      @borders = SimpleTypedList.new Border, 'borders'
      @borders << Border.new
      black_border = Border.new
      [:left, :right, :top, :bottom].each do |item|
        black_border.prs << BorderPr.new(:name=>item, :style=>:thin, :color=>Color.new(:rgb=>"FF000000"))
      end
      @borders << black_border
      @borders.lock

      @cellStyleXfs = SimpleTypedList.new Xf, "cellStyleXfs"
      @cellStyleXfs << Xf.new(:borderId=>0, :numFmtId=>0, :fontId=>0, :fillId=>0)
      @cellStyleXfs.lock

      @cellStyles = SimpleTypedList.new CellStyle, 'cellStyles'
      @cellStyles << CellStyle.new(:name =>"Normal", :builtinId =>0, :xfId=>0)
      @cellStyles.lock

      @cellXfs = SimpleTypedList.new Xf, "cellXfs"
      @cellXfs << Xf.new(:borderId=>0, :xfId=>0, :numFmtId=>0, :fontId=>0, :fillId=>0)
      @cellXfs << Xf.new(:borderId=>1, :xfId=>0, :numFmtId=>0, :fontId=>0, :fillId=>0)
      # default date formatting
      @cellXfs << Xf.new(:borderId=>0, :xfId=>0, :numFmtId=>14, :fontId=>0, :fillId=>0, :applyNumberFormat=>1)
      @cellXfs.lock

      @dxfs = SimpleTypedList.new(Dxf, "dxfs"); @dxfs.lock
      @tableStyles = TableStyles.new(:defaultTableStyle => "TableStyleMedium9", :defaultPivotStyle => "PivotStyleLight16"); @tableStyles.lock
    end
def load_default_styles
      @numFmts = SimpleTypedList.new NumFmt, 'numFmts'
      @numFmts << NumFmt.new(:numFmtId => NUM_FMT_YYYYMMDD, :formatCode=> "yyyy/mm/dd")
      @numFmts << NumFmt.new(:numFmtId => NUM_FMT_YYYYMMDDHHMMSS, :formatCode=> "yyyy/mm/dd hh:mm:ss")

      @numFmts.lock

      @fonts = SimpleTypedList.new Font, 'fonts'
      @fonts << Font.new(:name => "Arial", :sz => 11, :family=>1)
      @fonts.lock

      @fills = SimpleTypedList.new Fill, 'fills'
      @fills << Fill.new(Axlsx::PatternFill.new(:patternType=>:none))
      @fills << Fill.new(Axlsx::PatternFill.new(:patternType=>:gray125))
      @fills.lock

      @borders = SimpleTypedList.new Border, 'borders'
      @borders << Border.new
      black_border = Border.new
      [:left, :right, :top, :bottom].each do |item|
        black_border.prs << BorderPr.new(:name=>item, :style=>:thin, :color=>Color.new(:rgb=>"FF000000"))
      end
      @borders << black_border
      @borders.lock

      @cellStyleXfs = SimpleTypedList.new Xf, "cellStyleXfs"
      @cellStyleXfs << Xf.new(:borderId=>0, :numFmtId=>0, :fontId=>0, :fillId=>0)
      @cellStyleXfs.lock

      @cellStyles = SimpleTypedList.new CellStyle, 'cellStyles'
      @cellStyles << CellStyle.new(:name =>"Normal", :builtinId =>0, :xfId=>0)
      @cellStyles.lock

      @cellXfs = SimpleTypedList.new Xf, "cellXfs"
      @cellXfs << Xf.new(:borderId=>0, :xfId=>0, :numFmtId=>0, :fontId=>0, :fillId=>0)
      @cellXfs << Xf.new(:borderId=>1, :xfId=>0, :numFmtId=>0, :fontId=>0, :fillId=>0)
      # default date formatting
      @cellXfs << Xf.new(:borderId=>0, :xfId=>0, :numFmtId=>14, :fontId=>0, :fillId=>0, :applyNumberFormat=>1)
      @cellXfs.lock

      @dxfs = SimpleTypedList.new(Dxf, "dxfs"); @dxfs.lock
      @tableStyles = TableStyles.new(:defaultTableStyle => "TableStyleMedium9", :defaultPivotStyle => "PivotStyleLight16"); @tableStyles.lock
    end
Creates the default set of styles the exel requires to be valid as well as setting up the
 Axlsx::STYLE_THIN_BORDER