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: rspec.rb
    path of file: ./repos/active_delivery/lib/active_delivery/testing
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module ActiveDelivery
  class HaveDeliveredTo < RSpec::Matchers::BuiltIn::BaseMatcher
    attr_reader :delivery_class, :ev
    
    def message_expectation_modifier
      number_modifier = (@expected_number == 1) ? "once" : "#{@expected_number} times"
      case @expectation_type
      when :exactly then "exactly #{number_modifier}"
      when :at_most then "at most #{number_modifier}"
      when :at_least then "at least #{number_modifier}"
      end