class_docstr: Tests for `ExperimentIdMiddleware`.
class_docstr_tok: ["Tests","for","`","ExperimentIdMiddleware","`","."]
code: def _create_app(self):
      return experiment_id.ExperimentIdMiddleware(self._echo_app)
  
imports: import json
  import werkzeug
  from werkzeug import test
  from tensorboard import test
  from tensorboard.backend import experiment_id
label_desc: Use image node_id 1 for calling the ExperimentIdMiddlewareTest obj's underlying member method code with example usage: obj._create_app() and returns: experiment_id