railsチュートリアル8章にてrails testが通らない

Error:
UsersLoginTest#test_login_with_valid_information_followed_by_logout:
NoMethodError: undefined method `log_in' for #<SessionsController:0x00000000009010>
Did you mean?  login_url
    app/controllers/sessions_controller.rb:9:in `create'
    test/integration/users_login_test.rb:23:in `block in <class:UsersLoginTest>'


rails test test/integration/users_login_test.rb:21

require 'test_helper'

class UsersLoginTest < ActionDispatch::IntegrationTest

  def setup
    @user = users(:michael)
  end

  test "login with valid email/invalid password" do
    get login_path
    assert_template 'sessions/new'
    post login_path, params: { session: { email:    @user.email,
                                          password: "invalid" } }
    assert_not is_logged_in?
    assert_template 'sessions/new'
    assert_not flash.empty?
    get root_path
    assert flash.empty?
  end

  test "login with valid information followed by logout" do
    get login_path
    post login_path, params: { session: { email:    @user.email,
                                          password: 'password' } }
    assert is_logged_in?
    assert_redirected_to @user
    follow_redirect!
    assert_template 'users/show'
    assert_select "a[href=?]", login_path, count: 0
    assert_select "a[href=?]", logout_path
    assert_select "a[href=?]", user_path(@user)
    delete logout_path
    assert_not is_logged_in?
    assert_redirected_to root_url
    follow_redirect!
    assert_select "a[href=?]", login_path
    assert_select "a[href=?]", logout_path,      count: 0
    assert_select "a[href=?]", user_path(@user), count: 0
  end
end

class SessionsController < ApplicationController
  def new
  end

  def create
    user = User.find_by(email: params[:session][:email].downcase)
    if user&.authenticate(params[:session][:password])
    # ユーザーログイン後にユーザー情報のページにリダイレクトする
      log_in user
      redirect_to user
    else
      flash.now[:danger] = 'Invalid email/password combination'
      render 'new'
  end
end

  def destroy
    log_out
    redirect_to root_url
  end
end