def add_border(cell_ref, args = :all)
      cells = self[cell_ref]
      BorderCreator.new(self, cells, args).draw
    end
def add_border(cell_ref, args = :all)
      cells = self[cell_ref]
      BorderCreator.new(self, cells, args).draw
    end
Examples:
   add_border 'B2:F8', [:left, :top], :medium, '00330f'
   add_border 'B2:F8', [:left, :top], :medium
   add_border 'C2:G10', [:top]
   add_border 'C2:G10'
   add_border 'B2:D5', { style: :thick, color: '00330f', edges: [:left, :right] }