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: external_helpers.rb
    path of file: ./repos/middleman/middleman-core/lib/middleman-core/core_extensions
    
    the code of the file until where you have to start completion: module Middleman
  module CoreExtensions
    # Load helpers in `helpers/`
    class ExternalHelpers
    
      def after_configuration
        helpers_path = File.join(app.root, app.config[:helpers_dir])

        return unless File.exist?(helpers_path)

        glob = File.join(helpers_path, app.config[:helpers_filename_glob])
        ::Middleman::Util.glob_directory(glob).each do |filename|
          module_name = app.config[:helpers_filename_to_module_name_proc].call(filename)
          next unless module_name

          require filename
          next unless Object.const_defined?(module_name.to_sym)

          app.template_context_class.send :include, Object.const_get(module_name.to_sym)
        end
      end