code: def test_model_fit(self):
      ds = DS0()
      loader_train = elegy.data.DataLoader(
          ds, batch_size=4, n_workers=4
      )
      loader_valid = elegy.data.DataLoader(
          ds, batch_size=4, n_workers=4
      )
  
      class Module(elegy.Module):
          def __call__(self, x):
              x = jnp.mean(x, axis=[1, 2])
              x = elegy.nn.Linear(20)(x)
              return x
  
      model = elegy.Model(
          Module(),
          loss=elegy.losses.Crossentropy(),
          optimizer=optax.sgd(0.1),
      )
      model.fit(loader_train, validation_data=loader_valid, epochs=3)
  
imports: from unittest import TestCase
  import jax.numpy
  import numpy
  import optax
  import pytest
  import elegy
label_desc: Use image node_id 5 for calling the DataLoaderTestCase obj's underlying member method code with example usage: obj.test_model_fit() and returns: x