ichabod:~ uplime% pry
[1] pry(main)> class String
[1] pry(main)*   def length_squared
[1] pry(main)*     self.length * self.length
[1] pry(main)*   end
[1] pry(main)* end
=> :length_squared
[2] pry(main)> "abcd".length
=> 4
[3] pry(main)> "abcd".length_squared
=> 16