class_docstr: Tests for `ClientFeatureFlagsMiddleware`.
class_docstr_tok: ["Tests","for","`","ClientFeatureFlagsMiddleware","`","."]
code: def test_query_string_with_json_not_decodable(self):
      app = client_feature_flags.ClientFeatureFlagsMiddleware(
          self._echo_app
      )
      server = werkzeug_test.Client(app, wrappers.Response)
  
      with self.assertRaisesRegex(
          errors.InvalidArgumentError, "cannot be JSON decoded."
      ):
          response = server.get(
              "",
              query_string={
                  "tensorBoardFeatureFlags": "some_invalid_json {} {}",
              },
          )
  
imports: import json
  from werkzeug import test
  from werkzeug import wrappers
  from tensorboard import context
  from tensorboard import errors
  from tensorboard import test
  from tensorboard.backend import client_feature_flags
label_desc: Use image node_id 12 for calling the ClientFeatureFlagsMiddlewareTest obj's underlying member method code with example usage: obj.test_query_string_with_json_not_decodable() without return types