see how #clone copies singleton methods

clone_vs_dup.rb

irb(main):001:0> str = 'This is my STRING!'
=> "This is my STRING!"
irb(main):002:0> def str.-@
irb(main):003:1*   downcase
irb(main):004:1> end
=> :-@
irb(main):005:0> p str
"This is my STRING!"
=> "This is my STRING!"
irb(main):006:0> p -str
"this is my string!"
=> "this is my string!"
irb(main):007:0> s = str
=> "This is my STRING!"
irb(main):008:0> s.equal? str
=> true
irb(main):009:0> p -str
"this is my string!"
=> "this is my string!"
irb(main):010:0> ss = str.clone
=> "This is my STRING!"
irb(main):011:0> p -ss
"this is my string!"
=> "this is my string!"
irb(main):012:0> ss.equal? str
=> false
irb(main):013:0> sss = str.dup
=> "This is my STRING!"
irb(main):014:0> sss.equal? str
=> false
irb(main):015:0> p -sss
"This is my STRING!"
=> "This is my STRING!"