text: import unittest
  from aiohttp.test_utils import AioHTTPTestCase, unittest_run_loop
  from aiohttp import web
  
  
  negative_response = """{"status": "failed", "message": "\"Key not found: 'index'\""}"""
  
  
  class TestCase(AioHTTPTestCase):
      async def get_application(self):
          async def get_response(request):
              return web.Response(text=negative_response)
  
          app = web.Application()
          app.router.add_get('/', get_response)
          return app
  
      @unittest_run_loop
      async def test_nonnegative(self):
          resp = await self.client.request("GET", "/")
          assert resp.status == 200
          text = await resp.text()
          assert negative_response in text
  
  
  if __name__ == '__main__':
      TestCase()
  