Laravel 5 Testing with Authentication using L5 Helper Methods

Test.php

<?php

// === Inside my ApiTester.php Class. Could be inside the same test class but I use this for methods to test my API === //

/**
 * Set Up Method for Tests
 */
public function setUp()
{
    parent::setUp();

    Artisan::call('migrate');

    $this->session(array());
    $this->testSession = Session::all();
}

/**
 * Tear Down Method for Tests
 */
public function tearDown()
{
    parent::tearDown();
}

/**
 * Method to stub a new Task
 * Uses faker library to create mock content
 * 
 * @param array $fields
 *
 * @return array
 */
public function getStub($fields = array())
{
    return array_merge(array(
        'user_id'       => 1,
        'title'         => (string) $this->faker->sentence(3),
        'description'   => (string) $this->faker->realText(100),
        'completed'     => $this->faker->boolean()
    ), $fields);
}

/**
 * Method to create new User and then Authenticate the User
 * http://laravel.com/docs/5.0/testing#helper-methods
 */
public function getAuthenticatedUser()
{
    $user = new User(['name' => 'McTest', 'email' => 'mctest@example.com', 'password' => Hash::make('password')]);
    $this->be($user);
}

/**
 * Method to create new User and then Authenticate the User
 * http://laravel.com/docs/5.0/testing#helper-methods
 */
public function getAuthenticatedUser()
{
    $user = new User(['name' => 'McTest', 'email' => 'mctest@example.com', 'password' => Hash::make('password')]);
    $this->be($user);
}

/**
 * Method to return the _token for the Session to use during tests that need to
 * pass through the CSRF middleware
 *
 * @return array
 */
public function getSessionCsrftoken()
{
    return array( '_token' => $this->testSession['_token']);
}

// === In the test file itself. === //
/**
 * Test a new task is successfully created
 */
public function testItCreatesNewTaskGivenValidParameters()
{
    $this->getAuthenticatedUser();

    $this->getJson('api/v1/tasks', 'POST', array_merge($this->getStub(), $this->getSessionCsrftoken()));

    $this->assertResponseStatus(201);
}

I seem to be having a bit of a problem at the moment getting the tests to pass because it seems the

$this->flushSession();

in the tearDown() method is causing this error:

TasksTest::testItCreatesNewTaskGivenValidParameters
ReflectionException: Class session does not exist