Jeffrey Soong said about 4 years ago on Ruby Objects and Memoization :
can someone explain why do you need an instance method find to loop and find the record when the looping can be done in the class method? Wouldn't you be able to something like attached below?

class << self
 def find(id)
   return unless id
   new(USERS.find { |user| user[:id] == id })
 end
end