code: def model_and_losses():
      model = Sequential(
          [Dense(4, activation="linear", input_shape=(2,))]
      )
      losses = [(_DummyLoss(model), 1)]
      return model, losses
  
file_path: keras-vis/tests/vis/test_optimizer.py
imports: import pytest
  import keras.backend
  from keras.layers import Dense
  from keras.models import Sequential
  from vis.optimizer import Optimizer
  from vis.losses import Loss
label_desc: Use image node_id 1 for calling a global function with example usage: model_and_losses() and returns: model,  losses