def write_to(io)
      deduplicate

      io.write(@header_entry.to_s)

      @entries.each do |entry|
        io.write("\n")
        io.write(entry.to_s)
      end
    end
def write_to(io)
      deduplicate

      io.write(@header_entry.to_s)

      @entries.each do |entry|
        io.write("\n")
        io.write(entry.to_s)
      end
    end
Write the contents of this file to the specified IO object.
 @param [IO] io the IO object to write the contents of the file to.