Array.class_eval do
  def dump_to_excel(path)
    head, *body = *self
    workbook = Spreadsheet::Workbook.new
    worksheet = workbook.create_worksheet
    worksheet.row(0).default_format = Spreadsheet::Format.new(:weight => :bold)
    head.each_with_index do |label, index|
      worksheet[0, index] = label
      worksheet.column(index).width = 25
    end
    row_index = 1
    body.each do |row|
      row.each_with_index do |cell, cell_index|
        worksheet[row_index, cell_index] = cell
      end
      row_index += 1
    end
    workbook.write path
  end
end