def formats
      formats=[]
      f = self
      formats << f
      while f.parent
        formats << f.parent
        f = f.parent
      end
      formats.reverse
    end
def formats
      formats=[]
      f = self
      formats << f
      while f.parent
        formats << f.parent
        f = f.parent
      end
      formats.reverse
    end
returns an array of all formats this style is inheriting from (including itself)
 @return [Array<Workbook::Format>] an array of Workbook::Formats