example2.rb

#!/usr/bin/env ruby

require_relative 'version2'

v1 = Version1.new
v1.first_name = 'Mario'
v1.last_name = 'Carrion'

puts v1.columns
puts v1.values

# outputs
# last_name,first_name
# Carrion,Mario

v2 = Version2.new
v2.first_name = 'Mario'
v2.last_name = 'Carrion'
v2.age = 99 # :-)

puts v2.columns
puts v2.values

# outputs
# age,last_name,first_name
# 99,Carrion,Mario