code: def test_single_cem_input():
      model = Sequential()
      model.add(Flatten(input_shape=(2, 3)))
      model.add(Dense(2))
  
      memory = EpisodeParameterMemory(limit=10, window_length=2)
      agent = CEMAgent(
          model,
          memory=memory,
          nb_actions=2,
          nb_steps_warmup=5,
          batch_size=4,
          train_interval=50,
      )
      agent.compile()
      agent.fit(MultiInputTestEnv((3,)), nb_steps=100)
  
file_path: keras-rl/tests/rl/agents/test_cem.py
imports: from __future__ import division
  from __future__ import absolute_import
  import pytest
  import numpy
  from numpy.testing import assert_allclose
  from keras.models import Model, Sequential
  from keras.layers import Input, Dense, Flatten, Concatenate
  from rl.agents.cem import CEMAgent
  from rl.memory import EpisodeParameterMemory
  from rl.processors import MultiInputProcessor
  from ..util import MultiInputTestEnv
label_desc: Use image node_id 1 for calling a global function with example usage: test_single_cem_input() without return types