Example code from https://www.youtube.com/watch?v=SxHqhDT9WGI

savings_account.rb

class Account
  attr_reader :account_id, :initial_balance
  
  initialize(account_id, initial_balance)
    @account_id = account_id
    @initial_balance = initial_balance
  end
end

class SavingsAccount < Account
  
  def initialize(account_id, initial_balance)
    super(account_id, initial_balance)
  end
  private :initialize  
  
  # some methods
end