code: def test_backend_imports_correctly(self):
      backend = fastmath.backend()
      self.assertEqual(jnp, backend["np"])
      self.assertNotEqual(onp, backend["np"])
  
      self.override_gin("backend.name = 'numpy'")
  
      backend = fastmath.backend()
      self.assertNotEqual(jnp, backend["np"])
      self.assertEqual(onp, backend["np"])
  
imports: import collections
  from absl.testing import parameterized
  import gin
  import jax.numpy
  import numpy
  from tensorflow import test
  from trax import fastmath
label_desc: Use image node_id 3 for calling the BackendTest obj's underlying member method code with example usage: obj.test_backend_imports_correctly() without return types