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: helpers.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/actionpack-5.0.3/lib/abstract_controller
    
    the code of the file until where you have to start completion: require 'active_support/dependencies'

module AbstractController
  module Helpers
    extend ActiveSupport::Concern

    included do
      class_attribute :_helpers
      self._helpers = Module.new

      class_attribute :_helper_methods
      self._helper_methods = Array.new
    end

    class MissingHelperError < LoadError
      def initialize(error, path)
        @error = error
        @path  = "helpers/#{path}.rb"
        set_backtrace error.backtrace

        if error.path =~ /^#{path}(\.rb)?$/
          super("Missing helper file helpers/%s.rb" % path)
        else
          raise error
        end
      end
    end

    module ClassMethods
      # When a class is inherited, wrap its helper module in a new module.
      # This ensures that the parent class's module can be changed
      # independently of the child class's.
      def inherited(klass)
        helpers = _helpers
        klass._helpers = Module.new { include helpers }
        klass.class_eval { default_helper_module! } unless klass.anonymous?
        super
      end

      # Declare a controller method as a helper. For example, the following
      # makes the +current_user+ and +logged_in?+ controller methods available
      # to the view:
      #   class ApplicationController < ActionController::Base
      #     helper_method :current_user, :logged_in?
      #
      #     def current_user
      #       @current_user ||= User.find_by(id: session[:user])
      #     end
      #
      #     def logged_in?
      #       current_user != nil
      #     end
      #   end
      #
      # In a view:
      #  <% if logged_in? -%>Welcome, <%= current_user.name %><% end -%>
      #
      # ==== Parameters
      # * <tt>method[, method]</tt> - A name or names of a method on the controller
      #   to be made available on the view.
      def helper_method(*meths)
        meths.flatten!
        self._helper_methods += meths

        meths.each do |meth|
          _helpers.class_eval <<-ruby_eval, __FILE__, __LINE__ + 1
            def #{meth}(*args, &blk)                               # def current_user(*args, &blk)
              controller.send(%(#{meth}), *args, &blk)             #   controller.send(:current_user, *args, &blk)
            end                                                    # end
          ruby_eval
        end
      end

      # The +helper+ class method can take a series of helper module names, a block, or both.
      #
      # ==== Options
      # * <tt>*args</tt> - Module, Symbol, String
      # * <tt>block</tt> - A block defining helper methods
      #
      # When the argument is a module it will be included directly in the template class.
      #   helper FooHelper # => includes FooHelper
      #
      # When the argument is a string or symbol, the method will provide the "_helper" suffix, require the file
      # and include the module in the template class. The second form illustrates how to include custom helpers
      # when working with namespaced controllers, or other cases where the file containing the helper definition is not
      # in one of Rails' standard load paths:
      #   helper :foo             # => requires 'foo_helper' and includes FooHelper
      #   helper 'resources/foo'  # => requires 'resources/foo_helper' and includes Resources::FooHelper
      #
      # Additionally, the +helper+ class method can receive and evaluate a block, making the methods defined available
      # to the templat
    
      def helper_method(*meths)
        meths.flatten!
        self._helper_methods += meths

        meths.each do |meth|
          _helpers.class_eval <<-ruby_eval, __FILE__, __LINE__ + 1
            def #{meth}(*args, &blk)                               # def current_user(*args, &blk)
              controller.send(%(#{meth}), *args, &blk)             #   controller.send(:current_user, *args, &blk)
            end                                                    # end
          ruby_eval
        end
      end

      # The +helper+ class method can take a series of helper module names, a block, or both.
      #
      # ==== Options
      # * <tt>*args</tt> - Module, Symbol, String
      # * <tt>block</tt> - A block defining helper methods
      #
      # When the argument is a module it will be included directly in the template class.
      #   helper FooHelper # => includes FooHelper
      #
      # When the argument is a string or symbol, the method will provide the "_helper" suffix, require the file
      # and include the module in the template class. The second form illustrates how to include custom helpers
      # when working with namespaced controllers, or other cases where the file containing the helper definition is not
      # in one of Rails' standard load paths:
      #   helper :foo             # => requires 'foo_helper' and includes FooHelper
      #   helper 'resources/foo'  # => requires 'resources/foo_helper' and includes Resources::FooHelper
      #
      # Additionally, the +helper+ class method can receive and evaluate a block, making the methods defined available
      # to the template.
      #
      #   # One line
      #   helper { def hello() "Hello, world!" end }
      #
      #   # Multi-line
      #   helper do
      #     def foo(bar)
      #       "#{bar} is the very best"
      #     end
      #   end
      #
      # Finally, all the above styles can be mixed together, and the +helper+ method can be invoked with a mix of
      # +symbols+, +strings+, +modules+ and blocks.
      #
      #   helper(:three, BlindHelper) { def mice() 'mice' end }
      #
      def helper(*args, &block)
        modules_for_helpers(args).each do |mod|
          add_template_helper(mod)
        end

        _helpers.module_eval(&block) if block_given?
      end

      # Clears up all existing helpers in this class, only keeping the helper
      # with the same name as this class.
      def clear_helpers
        inherited_helper_methods = _helper_methods
        self._helpers = Module.new
        self._helper_methods = Array.new

        inherited_helper_methods.each { |meth| helper_method meth }
        default_helper_module! unless anonymous?
      end

      # Returns a list of modules, normalized from the acceptable kinds of
      # helpers with the following behavior:
      #
      # String or Symbol:: :FooBar or "FooBar" becomes "foo_bar_helper",
      # and "foo_bar_helper.rb" is loaded using require_dependency.
      #
      # Module:: No further processing
      #
      # After loading the appropriate files, the corresponding modules
      # are returned.
      #
      # ==== Parameters
      # * <tt>args</tt> - An array of helpers
      #
      # ==== Returns
      # * <tt>Array</tt> - A normalized list of modules for the list of
      #   helpers provided.
      def modules_for_helpers(args)
        args.flatten.map! do |arg|
          case arg
          when String, Symbol
            file_name = "#{arg.to_s.underscore}_helper"
            begin
              require_dependency(file_name)
            rescue LoadError => e
              raise AbstractController::Helpers::MissingHelperError.new(e, file_name)
            end

            mod_name = file_name.camelize
            begin
              mod_name.constantize
            rescue LoadError
              # dependencies.rb gives a similar error message but its wording is
              # not as clear because it mentions autoloading. To the user all it
              # matters is that a helper module couldn't be loaded, autoloading
              # is an internal mechanism that should not leak.
              raise NameError, "Couldn't find #{mod_name}, expected it to be defined in helpers/#{file_name}.rb"
            end
          when Module
            arg
          else
            raise ArgumentError, "helper must be a String, Symbol, or Module"
          end
        end