Faker::Kpop.i_groups # 1990's og groups => "Seo Taiji and Boys"
Faker::Kpop.ii_groups # 2000's groups => "Girls' Generation"
Faker::Kpop.iii_groups # 2010's groups => "Trouble Maker"
Faker::Kpop.girl_groups # girl groups => "2NE1"
Faker::Kpop.boy_bands # boy bands => "Exo"
Faker::Kpop.solo # solo artists => "T.O.P"