n2example.rb

class User < ApplicationRecord
  
  def savings_account
    self.accounts.where(savings: true).first || NullAccount.new
  end
  
  def chequing_account
    self.accounts.where(chequing: true).first || NullAccount.new
  end

  def investment_account
    self.accounts.where(investment: true).first || NullAccount.new
  end

end