You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: error_simulator.rb
    path of file: ./repos/identity-idp/lib/telephony/test
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Telephony
  module Test
    class ErrorSimulator
      OPT_OU
    
      def error_for_number(number)
        cleaned_number = number.gsub(/^\+1/, '').gsub(/\D/, '')
        case cleaned_number
        when '2255551000'
          TelephonyError.new('Simulated telephony error')
        when '225555300'
          InvalidPhoneNumberError.new('Simulated phone number error')
        when '2255552000'
          InvalidCallingAreaError.new('Simulated calling area error')
        when OPT_OUT_PHONE_NUMBER
          OptOutError.new('Simulated opt out error')
        end