new_contents: """
  
  """
  import time
  import logging
  import unittest
  
  from flask import Flask
  import mock
  
  from flask.ext.limiter.extension import C, Limiter
  
  
  class RegressionTests(unittest.TestCase):
  
      def build_app(self, config={}, **limiter_args):
          app = Flask(__name__)
          for k,v in config.items():
              app.config.setdefault(k,v)
          limiter = Limiter(app, **limiter_args)
          mock_handler = mock.Mock()
          mock_handler.level = logging.INFO
          limiter.logger.addHandler(mock_handler)
          return app, limiter
  
      def test_redis_request_slower_than_fixed_window(self):
          app, limiter = self.build_app({
              C.GLOBAL_LIMITS : "5 per second",
              C.STORAGE_URL: "redis://localhost:6379",
              C.STRATEGY: "fixed-window"
          })
  
          @app.route("/t1")
          def t1():
              time.sleep(1.1)
              return "t1"
  
          with app.test_client() as cli:
              self.assertEqual(200, cli.get("/t1").status_code)
  
      def test_redis_request_slower_than_moving_window(self):
          app, limiter = self.build_app({
              C.GLOBAL_LIMITS : "5 per second",
              C.STORAGE_URL: "redis://localhost:6379",
              C.STRATEGY: "moving-window"
          })
  
          @app.route("/t1")
          def t1():
              time.sleep(1.1)
              return "t1"
  
          with app.test_client() as cli:
              self.assertEqual(200, cli.get("/t1").status_code)
  
subject: Add test cases for 500 error with slow responses