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: formatter.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/actionpack-5.0.3/lib/action_dispatch/journey
    
    the code of the file until where you have to start completion: require 'action_controller/metal/exceptions'

module ActionDispatch
  # :stopdoc:
  module Journey
    # The Formatter class is used for formatting URLs. For example, parameters
    # passed to +url_for+ in Rails will eventually call Formatter#generate.
    class Formatter
      attr_reader :routes

      def initia
    
        def extract_parameterized_parts(route, options, recall, parameterize = nil)
          parameterized_parts = recall.merge(options)

          keys_to_keep = route.parts.reverse_each.drop_while { |part|
            !options.key?(part) || (options[part] || recall[part]).nil?
          } | route.required_parts

          parameterized_parts.delete_if do |bad_key, _|
            !keys_to_keep.include?(bad_key)
          end

          if parameterize
            parameterized_parts.each do |k, v|
              parameterized_parts[k] = parameterize.call(k, v)
            end
          end