def headings= arrays
      arrays = [arrays] unless arrays.first.is_a?(Array)
      @headings = arrays.map do |array|
        row = Row.new(self, array)
        require_column_widths_recalc
        row
      end
    end
def headings= arrays
      arrays = [arrays] unless arrays.first.is_a?(Array)
      @headings = arrays.map do |array|
        row = Row.new(self, array)
        require_column_widths_recalc
        row
      end
    end
Set the headings