def predefined_styles
      @predefined_styles ||=
          begin
            tmp = {}
            styles do |s|
              tmp = {
                  bold:       s.add_style(b: true, alignment: { vertical: :top }),
                  date:       s.add_style(format_code: 'mm/dd/yyyy', alignment: { vertical: :top }),
                  float:      s.add_style(format_code: '#,##0.00', alignment: { vertical: :top }),
                  integer:    s.add_style(format_code: '#,##0', alignment: { vertical: :top }),
                  percent:    s.add_style(num_fmt: 9, alignment: { vertical: :top }),
                  currency:   s.add_style(num_fmt: 7, alignment: { vertical: :top }),
                  text:       s.add_style(format_code: '@', alignment: { vertical: :top }),
                  wrapped:    s.add_style(alignment: { wrap_text: true, vertical: :top }),
                  normal:     s.add_style(alignment: { vertical: :top })
              }
            end
            tmp
          end
    end
def predefined_styles
      @predefined_styles ||=
          begin
            tmp = {}
            styles do |s|
              tmp = {
                  bold:       s.add_style(b: true, alignment: { vertical: :top }),
                  date:       s.add_style(format_code: 'mm/dd/yyyy', alignment: { vertical: :top }),
                  float:      s.add_style(format_code: '#,##0.00', alignment: { vertical: :top }),
                  integer:    s.add_style(format_code: '#,##0', alignment: { vertical: :top }),
                  percent:    s.add_style(num_fmt: 9, alignment: { vertical: :top }),
                  currency:   s.add_style(num_fmt: 7, alignment: { vertical: :top }),
                  text:       s.add_style(format_code: '@', alignment: { vertical: :top }),
                  wrapped:    s.add_style(alignment: { wrap_text: true, vertical: :top }),
                  normal:     s.add_style(alignment: { vertical: :top })
              }
            end
            tmp
          end
    end
Gets the predefined style list.

 The +predefined_styles+ hash contains :bold, :date, :float, :integer, :percent, :currency, :text, :wrapped, and :normal
 styles for you to use.