old_contents: from flask import Flask
  from flask.ext.testing import TestCase
  
  import base64_utils
  
  
  class BaseTestCase(TestCase):
      def create_app(self):
          app = Flask(__name__)
          app.config['TESTING'] = True
          app.config['SECRET_KEY'] = 'TEST'
          app.register_blueprint(base64_utils.base64_utils)
          return app
  
  
  class AppTestCase(BaseTestCase):
      def test_page_load(self):
          rv = self.client.get("/")
          self.assertEqual(rv.status_code, 200)
  
new_contents: from flask import Flask
  from flask.ext.testing import TestCase
  
  import base64_utils
  
  
  class BaseTestCase(TestCase):
      def create_app(self):
          app = Flask(__name__)
          app.config['TESTING'] = True
          app.config['WTF_CSRF_ENABLED'] = False
          app.register_blueprint(base64_utils.base64_utils)
          return app
  
  
  class AppTestCase(BaseTestCase):
      def test_page_load(self):
          rv = self.client.get("/")
          self.assertEqual(rv.status_code, 200)
  
subject: Disable CSRF when testing.