def initialize(wb, options={})
      self.workbook = wb
      @sheet_protection = nil
      initialize_page_options(options)
      parse_options options
      @workbook.worksheets << self
      @sheet_id = index + 1
      yield self if block_given?
    end
Creates a new worksheet.
@note the recommended way to manage worksheets is Workbook#add_worksheet
@see Workbook#add_worksheet
@option options [String] name The name of this worksheet.
@option options [Hash] page_margins A hash containing page margins for this worksheet. @see PageMargins
@option options [Hash] print_options A hash containing print options for this worksheet. @see PrintOptions
@option options [Hash] header_footer A hash containing header/footer options for this worksheet. @see HeaderFooter
@option options [Boolean] show_gridlines indicates if gridlines should be shown for this sheet.