code: def testMSELoss(
      self,
      target: Union[float, onp.array],
      prediction: Union[float, onp.array],
      expected: Union[float, onp.array],
  ):
      actual = losses.mse_loss(target, prediction)
      onp.testing.assert_equal(actual, expected)
  
file_path: dopamine/tests/dopamine/jax/losses_test.py
imports: from typing import Optional, Union
  from absl.testing import absltest
  from absl.testing import parameterized
  from dopamine.jax import losses
  import numpy
label_desc: Use image node_id 2 for calling the LossesTest obj's underlying member method code with example usage: obj.testMSELoss(target, prediction, expected) without return types