class_docstr: Tests for `ClientFeatureFlagsMiddleware`.
class_docstr_tok: ["Tests","for","`","ClientFeatureFlagsMiddleware","`","."]
code: def test_header_feature_flags_take_precedence(self):
      app = client_feature_flags.ClientFeatureFlagsMiddleware(
          self._echo_app
      )
      server = werkzeug_test.Client(app, wrappers.Response)
  
      response = server.get(
          "",
          headers=[
              (
                  "X-TensorBoard-Feature-Flags",
                  '{"a": "1", "b": "2"}',
              )
          ],
          query_string={
              "tensorBoardFeatureFlags": '{"a": "2", "c": "3"}'
          },
      )
      self._assert_ok(
          response,
          {
              "a": "1",
              "b": "2",
              "c": "3",
          },
      )
  
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 15 for calling the ClientFeatureFlagsMiddlewareTest obj's underlying member method code with example usage: obj.test_header_feature_flags_take_precedence() without return types